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PREFACE. 


i 


This  work  is  offered  to  the  public  in  the  hope  that  it  has 
some  desirable  features  as  a text-book,  not  found  in  any  of  the 
able  elementary  works  on  Anatomy  and  Physiology  now  ex- 
tant. One  is,  the  introduction  of  more  of  microscopic  anat- 
omy than  is  usual.  Another  is,  a large  addition  on  Com- 
parative Anatomy,  which  is  now  become  a science  of  great 
importance.  A third  is,  the  Religious  Applications  of  these 
sciences ; which,  although  all  will  acknowledge  to  be  emi- 
nently appropriate,  we  have  found  in  no  elementary  treatise. 

We  make  no  pretensions  to  distinguished  attainments  or 
reputation  in  these  sciences,  as  a reason  for  writing  this  book. 
But  both  of  us  have  for  a great  number  of  years  been  in  the 
habit  of  hearing  recitations  and  giving  lectures  upon  them  in 
the  College  and  the  Academy,  and  we  ought  to  know  what 
sort  of  a text-book  is  needed.  But  we  dare  not  boast  that  we 
have  come  up  to  our  ideal.  We  have  tried  to  give  a condensed 
yet  clear  exhibition  of  the  leading  principles  and  facts,  which 
are  detailed  in  such  works  as  Carpenter’s  Human  Physiology, 
his  Comparative  Physiology,  Hassall’s  Microscopic  Anatomy, 
Griffith  and  Henfrey’s  Micrographic  Dictionary,  Peaslee’s 
Histology,  Todd  and  Bowman’s  Physiological  Anatomy,  Wil- 
son’s and  Gray’s  Anatomy,  Draper’s,  Dunglinson’s,  and  Dal- 
ton’s Physiologies,  Van  Der  Hoeven’s  Zoology,  and  the  works 
of  Cuvier,  Owen,  Agassiz,  Wyman,  Leidy,  and  Wagner  on 
Comparative  Anatomy. 


Through  the  liberality  of  the  publishers  we  are  able  to  pre- 
sent unusually  full  illustrations  of  subjects,  which  could  other- 
wise be  only  imperfectly  comprehended  by  the  learner. 

Many  of  the  drawings  contain  more  minute  details  of 
the  parts  represented  than  are  described  in  the  text.  The  in- 
structor can  require  these  to  be  recited  or  not,  as  he  pleases, 
according  to  the  age  and  ability  of  the  pupil.  So  as  to  the 
parts  on  Comparative  Anatomy,  as  they  are  distinctly  sepa- 
rated from  the  rest,  they  can,  if  desired,  be  passed  over  in  re- 
citation. 

At  the  earnest  solicitation  of  my  son,  my  name  stands  first 
on  the  title-page.  But  justice  requires  me  to  state  that  most 
of  the  body  of  the  work  has  been  prepared  by  him.  I have 
supposed  it  most  appropriate  that  it  should  be  so,  since  he  has, 
and  I have  not,  passed  regularly  through  the  medical  school. 
Yet  perhaps  the  public  may  have  some  confidence  in  my  judg- 
ment as  a teacher  for  more  than  forty  years,  in  shaping  the 
materials  so  as  to  be  best  adapted  for  purposes  of  instruction. 
But  aware,  in  some  measure,  of  our  deficiencies  and  imperfec- 
tions, neither  of  us,  in  sending  forth  the  work,  feels  it  to  be 
beyond  criticism  and  improvement.  In  a field  so  wide,  where 
so  many  are  pushing  their  investigations,  and  the  highest 
authorities  so  frequently  change  their  views,  we  do  not  ex- 
pect to  avoid  all  mistakes ; but  in  our  successive  editions, 
we  shall  correct  all  errors  which  we  find,  and  try  to  incorpor- 
ate the  new  discoveries. 

Edward  Hitchcock. 


Amherst  College  July,  1860. 


CONTENTS. 

PAGB 

Preliminary  Definitions  and  Principles 5 

CHAPTER  I. 

Osteology  and  Syndesmology  — Description  op  the  Bones  and 

Ligaments 31 

CHAPTER  II. 

Myology — Description  op  the  Muscles lOY 

- CHAPTER  III. 

Splanchnology — Description  op  the  Digestive  Organs. 155 

CHAPTER  IV. 

Angiology — Description  op  the  Heart,  Blood,  and  Blood-Yessels,  201 

CHAPTER  V. 

Pneumonology — Description  op  the  Organs  of  Breathing 244 

CHAPTER  VI. 


ICHOROLOGY — DESCRIPTION  OP  THE  ORGANS  OF  SECRETION 


282 


VI 


CONTENTS 


/ CHAPTER  VII. 

PAGE 

Neurology — Description  of  the  Brain  and  Nerves 316 

CHAPTER  VIII. 

The  Inlets  to  the  Soul — The  Senses 361 

CHAPTER  IX. 

Reugious  Infeeences  from  Anatomy  and  Physiology 420 


DEFINITIONS  AND  PRINCIPLES. 


1.  All  the  objects  in  the  material  world  are  divided  into 
Organic  and  Inorganic. 

2.  Cells,  Membranes,  and  Fibers. — In  organic  bodies,  the 
matter  composing  them  is  arranged  in  the  form  of  cells,  mem^ 
branes,  and  fibers,  variously  combined.  In  inorganic  bodies, 
though  the  particles  are  often  arranged  with  mathematical 
precision  in  particular  modes,  cells,  membranes,  and  fibers 
are  not  formed. 

3.  Life. — The  principle  of  life  is  always  associated  Avith  or- 
ganic, but  never  with  inorganic  bodies. 

4.  Examples  of  Organic  and  Inorganic  Objects. — Or- 
ganic bodies  embrace  Animals  and  Plants  ; every  thing  else  in 
the  material  world  is  inorganic,  as,  air,  water,  minerals,  rocks, 
and  soils. 

5.  Man  the  Head  of  the  Animal  Kingdom. — ‘‘Man  is 
the  end  toward  which  all  the  animal  kingdom  has  tended 
from  the  first  appearance  of  the  Palaeozoic  fishes/’ — Agassiz 
and  Gould. 

6.  Anatomy  and  Physiology. — Anatomy  is  the  science  that 

Questions.  1 Give  the  two  kingdoms  of  the  material  world.  2.  What  is  the  arrange- 
ment of  matter  in  organic  and  inorganic  bodies?  3.  With  which  is  life  associated? 
4 State  some  examples  of  organic  and  inorganic  bodies.  5.  Why  is  man  placed  at  the 
head  of  the  animal  kingdom  ? 6.  Define  Anatomy. 


G 


II  l T C ir  C O CMC  ’ S ANA  T O .M  Y 


describes  the  different  organs  of  animals.  Physiology  describes 
their  functions,  or  uses.  If  the  organs  of  man  alone  be  de- 
scribed, the  science  is  called  Human  Anatomy  and  Physiology. 
If  the  description  embrace  the  lower  animals,  it  is  called  Com- 
parative Anatomy  and  Physiology. 

7.  Another  definition  of  Anatomy,  is  the  science  of  Organ- 
ization ; and  of  Physiology,  the  science  of  Life. 

8.  Animal  and  Vegetable  Anatomy  and  Physiology.— 
There  are  also  such  sciences  as  Vegetable  Anatomy  and 
Physiology.  Indeed,  there  is  a strong  analogy  between  the 
organs  of  plants  and  animals,  and  their  uses.  Nor  is  it  easy 
always  to  draw  the  line  between  plants  and  animals,  where 
they  approach  the  nearest  to  each  other. 

9.  Intimate  Connection  of  Anatomy  and  Physiology. — 
Few  writers  confine  themselves  to  the  structure  of  animals, 
when  treating  of  their  anatomy,  but  treat  also  of  the  function 
of  their  organs ; and  the  same  thing  is  still  more  generally 
true  of  writers  on  physiology.  We  do  not  separate  these 
sciences  in  this  treatise. 

10.  Fifteen  Chemical  Elements  in  the  Unman  Body. — Of 
the  sixty-five  chemical  elements  or  simple  bodies  known  to 
exist,  only  fifteen  have  been  found  as  normal  constituents  of 
the  human  body.  The  following  is  the  list : — 


1.  Oxygen, 

2.  Hydrogen, 

3.  Carbon, 

4.  Nitrogen, 

5.  Sulphur, 


6.  Phosphorus, 
'I.  Calcium, 

8.  Magnesium, 

9.  Sodium, 

10.  Potassium, 


11.  Chlorine, 

12.  Pluorine, 

13.  Silicon, 

14.  Iron, 

15.  Manganese. 


11.  Carbon,  Hydrogen,  Oxygen,  and  Nitrogen. — The  first 
three  of  the  above  elements  are  found  in  all  the  solids  and  fluids 
of  the  body,  without  exception.  The  first  four  occur  in  all  the 

What  is  Physlolofry  ? When  is  the  term  comparative  applied?  7.  Oive.  a more  con- 
cise definition  of  AnatoTny  and  Physiology.  8.  Describe  animal  and  vegetable  IMiy- 
Biology.  0 Speak  of  the  close  relationship  between  Anatomy  and  Physiology.  State 
the  whole  nnmber  of  chemical  Elements,  10.  State  those  which  are  found  in  the  human 
body.  11.  Where  are  the  first  throe  found?  Nitrogen  also  ? 


AND  PHYSIOLOGY. 


7 


solid  parts,  and  in  all  the  fluids  except  fat.  They  form  the 
chief  and  most  important  ingredients  in  animals  and  plants. 

12.  Sulphur  and  Phosphorus,  illagiicsium,  Sodium,  Pot- 
assium, CMorine,  Fluorine,  Calcium,  Silicon,  Iron,  Man- 
ganese,— With  scarcely  an  exception,  these  elements  exist  in 
the  body  as  compounds;  that  is,  two  or  more  of  them  are 
combined,  as  in  water,  in  oxyds,  and  in  various  salts.  Sul- 
phur and  phosphorus  exist  in  albumen  and  fibrine,  as  well  as 
in  the  brain,  about  yjoth  of  its  weight  being  phosphorus. 
Bones  are  more  than  half  made  up  of  Phosphate  of  Lime,  and 
they  contain  a small  per  cent,  of  Phosphate  of  Magnesia. 
Sodium,  in  the  form  of  a chlorid  (common  salt),  is  found  in 
every  solid  and  fluid  of  the  body.  Potassium  occurs  as  a 
chlorid  in  the  muscles,  and  as  an  oxyd  in  salts.  Chlorine 
forms  chlorohydric  acid  by  combining  with  hydrogen  in  the 
gastric  juice.  Fluorine  exists  in  the  bones  in  a minute  quan- 
tity, combined  with  calcium.  Silicon  is  found  in  small  quan- 
tities in  hair,  wool,  and  feathers,  as  silica.  Iron  forms  about 
the  2000th  part  of  the  blood,*and  it  exists  also  in  the  muscles, 
hair,  and  milk.  Manganese,  in  small  quantities,  has  been 
detected  in  bone,  and  perhaps  in  the  hair. 

13.  Copper,  lead,  and  Arsenic. — Copper,  lead,  and  arsenic 
have  been  detected  in  minute  quantity  in  human  flesh.  But 
it  is  not  probable  that  they  are  normal  constituents. 

14.  Inferences. — From  these  facts  we  learn  that  our  food 
and  drink  should  contain  the  fifteen  ingredients  above  described. 
Milk  and  eggs  are  the  only  articles  that  do  contain  them  all ; 
and  hence,  the  importance  of  variety  in  diet.  And  the  fact 
that  we  are  obliged  to  use  ten  mineral  ingredients  in  our  food, 
shows  the  absurdity  of  a prevalent  prejudice  that  no  mineral 
should  ever  be  taken  as  a medicine. 

15.  Immediate  Principles. — As  they  exist  in  the  body,  the 

12.  State  in  what  organs  Sulphur  and  Phosphorus  are  found.  What  is  one  of  the  prin- 
cii)al  ingredients  of  bones  ? Where  is  Chlorine  found  ? Fluorine  ? Silicon  ? In  what 
parts  of  the  body  is  Iron  found?  13.  What  is  to  be  said  of  Copper,  Lead  and  Arsenic? 
14.  What  should  our  food  contain?  Are  mineral  ingredients  always  poisonous ? 15.  De- 
fine Immediate  Principles. 


8 


HITCHCOCK’S  ANATOMY 


fifteen  elements  above  described  form  a largo  number  of  com- 
pounds, called  Immediate  Principles,  or  Organic  Radicals. 
They  exist  naturally,  and  can  be  separated  anatomically,  that 
is,  mechanically,  from  one  another ; but  the  divisions  can  bo 
carried  no  further  'without  chemical  decomposition.  A few 
elementary  substances  found  in  the  system,  as,  oxygen,  hydro- 
gen, and  nitrogen,  are  sometimes  called  Immediate  Principles. 

16.  Immediate  Prineiples  Chemically  Grouped. — We  arc 
certain  that  eighty-four  of  these  principles  have  been  found  in 
the  human  system.  If  we  group  them  according  to  their  chem- 
ical characters,  they  will  fall  into  the  following  divisions. 
Half  of  them  are  the  result  of  the  waste  or  metamorphosis  of 
the  substance  of  the  body  ; ll:o  other  half  exist  independently 
of  any  such  change. 

1.  Gascons^  and  not  saline : Oxygen,  Hydrogen,  Nitro- 
gen, Carbonic  Acid,  and  Water. 

2.  Salts : Chlorids  (2),  Fluoride  of  Calcium,  Hydrochlo- 
rate of  Ammonia,  Carbonates  (4),  Bicarbonate  of  Soda,  Sul- 
phates (3),  Phosphates  (7),  Lactates  (3),  Oxalate  of  Lime, 
Urates  (5),  Hippurates  (3),  Inosate  of  Potassa,  Pneumate 
of  Soda,  Taurochlorate  of  Soda,  Hyocholinate  of  Soda,  Gly- 
cocholate  of  Soda,  Oleate  of  Soda,  Margarate  of  Soda,  Stear- 
ate of  Soda,  Caproate  of  Potassa,  Soda,  &c. 

3.  Acids:  Lactic,  Uric,  Hippuric,  Pneumic,  Lithofallic, 
Margaric,  and  Stearic. 

4.  Neutral  Nitrogeyious  Comi^ounds : Creatine,  Urea, 
Cystine,  and  Creatinine. 

5.  Neutral  Non-Nitrogenous  Compotmds : Sugar  from 
the  Liver,  and  Sugar  of  Milk. 

6.  Fatty  and  Saponaceous  Compounds  : Cholesterine, 
Oleic  Acid,  Stearic  Acid,  Oleine,  Stearine,  &c.  (13.) 

7.  Coagulahic  Principles : Fibrine,  Albumen,  Caseine, 
Clobuline,  Musculine,  Osteine,  Keratine,  Hematine,  &c.  (18.) 


10.  Stuto  tho  nutnbcT  of  these  principles  that  have  been  already  found.  What  are 
one  half  of  them  derived  from  ? Give  tho  first  group,  or  the  gaseous  ones.  State  th« 
bulls.  The  Acids.  The  4th,  Dth,  Gtli  and  7tb  classes. 


AND  PIIA-SIOLOGY. 


9 


17.  Immediate  Principles  Physiologically  Grouped. — • 
If  we  group  the  preceding  substances  according  to  their  phy- 
siological relations,  we  might,  with  Dr.  Carpenter,  bring  them 
all  into  four  divisions. 

1.  Hlstogenetic  Substances^  or  such  as  are  converted  into 
animal  substances,  and  are  nitrogenous. 

2.  Calorific  Substances,  mainly  intended  to  produce  heat, 
and  are  non-nitrogenous,  as,  sugar  and  oils. 

3.  The  co7nponents  of  the  living  animal  substance, 

4.  Excrementitious  Substances,  formed  Avithin  the  body, 
and  thrown  out  of  it. 

18.  Other  Probable  Principles. — Quite  a number  of  other 
substances  have  been  detected  in  the  human  system,  Avhich 
some  regard  as  immediate  principles.  But  it  is  safer  to  Avait 
till  further  examination  has  removed  doubt. 

19.  Several  of  the  above  principles  are  capable  of  crystal- 
lization, and  are  some- 
times found  in  that  state 
in  the  body.  Figs.  1 
and  2 shoAV  two  exam- 
ples of  these  crystals, 
the  first  of  Hippuric 
acid,  and  the  other  of 
Creatine. 

20.  To  go  into  minute 
details  respecting  the  im- 
mediate principles  above 
described,  Avould  occupy 
too  much  space  in  a work 
like  the  present.  But  a 
fcAV  statements  respect- 
ing the  most  import- 

17.  AAHiat  are  the  Groups  of  these  substances  when  physiologically  grouped  ? Who  is 
the  autliority  for  this?  Define  the  llistogenetic  and  the  Calorific  group.  What  are  ex* 
creincntitious  substances?  Are  there  any  other  principles  in  the  body? 

1* 


Fig.  1. 


10 


HITCHCOCK’S  ANATOMY 


ant  of  them  seem  desir- 
able. 

21.  Oxj ‘rni.  — Oxy- 
gen is  regarded  as  an 
immediate  principle  only 
when  it  exists  in  a free 
state,  as  it  does  in  the 
blood,  which,  in  an 
adult,  contains  sixty- 
one  grains : nine  and 
a half  cubic  inches  be- 
ing found  in  the  arte- 
rial, and  fourteen  and  a 
half  in  the  venous  blood. 
An  adult  consumes  in  a year  about  eight  hundred  pounds  of 
oxygen.  An  inhabitant  of  a mountainous  region  18,000  feet 
above  the  sea  (in  Potosi)  consumes,  however,  only  two  thirds 
as  much  as  one  upon  the  sea-shore. 

22.  Hydrogen  and  Nitrogen. — Hydrogen  is  found  in  a free 
state  in  the  stomach  and  some  parts  of  the  intestines,  and 
nitrogen  in  the  lungs,  blood,  and  intestines. 

23.  Carbonic  Acid. — Carbonic  acid  is  found  in  the  lungs, 
the  alimentary  canal,  the  blood,  and  urine. 

24.  Water;  Cubical  Size  of  the  Body. — Water  enters  into 
the  composition  of  every  fluid,  and  every  solid  in  the  body. 
The  bulk  of  the  body,  upon  an  average,  is  equal  to  a cube  of  a 
little  more  than  sixteen  inches  on  a side  ; and  the  amount  of 
water  equals  a cube  a little  more  than  fourteen  inches  on  a 
side,  or  nearly  three  fourths  of  the  body.  Every  part,  ex- 
cept bone,  enamel,  teeth,  tendon,  dry  cuticle,  and  elastic  tis- 
sue, is  more  than  half  water. 

21.  How  imicli  Oxygon  by  woitrbt  is  I’oiind  in  the  body?  What  bulk  of  oxygen  is  found 
In  the  venonsand  wliat  in  the  arterial  blood  ? How  much  does  an  adult  consume  by  re- 
sidration  nnd  (»therwise  in  a year?  What  effect  does  elevation  above  the  sea  have  upon 
the  ainoimt  eonsurned?  22.  State  bow  Hydrogen  and  Nitrogen  are  found.  23.  Carbonic 
acid  .also.  24  How  important  a constituent  is  water?  Give  the  size  of  the  body  if  re- 
duced to  a cube.  If  this  cube  were  water,  how  largo  would  it  bo  ? 


Fig.  2. 


AND  r II  Y S I O L O G Y . 


11 


25.  Amount  of  Water  Consumed  Yearly  by  an  Adult. — 
An  adult  drinks  about  fifteen  hundred  pounds  of  water  yearly; 
and  throws  ofl*  through  the  various  waste-gates  nineteen  hun- 
dred pounds.  The  difficulty  of  accounting  for  the  four  hun- 
dred pounds  has  led  some  to  suppose  that  water  is  formed  in 
the  system  by  the  union  of  oxygen  and  hydrogen. 

26.  Common  Salt  in  the  Body. — The  salts  that  have  been 
enumerated,  are  found  in  almost  every  part  of  the  body.  Com- 
mon salt  (Chlorid  of  Sodium)  is  found  in  every  fluid  and  solid, 
except  enamel.  The  whole  amount  in  man  h 277  grains.  It 
subserves  many  important  uses. 

27.  Carbonate  and  Phosphate  of  Lime,  Ac. — Carbonate 
of  lime  exists  in  considerable  quantity  in  the  bon.es,  along 
with  a much  larger  quantity  of  the  phosphate  of  lime,  and  a 
small  amount  of  phosphate  of  magnesia,  and  of  fluoride  of 
calcium.  These  salts,  except  the  fluoride,  are  found  in  most 
other  parts  of  the  body. 

28.  Acids,  Salts,  &c . — Most  of  the  acids  and  salts,  the  neu- 
tral nitrogenous  compounds,  the  sugars,  the  fatty  and  sapona- 
ceous compounds,  exist,  or  are  formed  in  the  fluids  of  the 
body,  and  though  numerous  (forty-two  in  all),  their  quantity 
is  comparatively  small.  They  are  mostly  formed  by  disassimi- 
lation  in  the  body,  and  hence  only  their  elements  need  to 
exist  in  our  food. 

29.  Sugar  in  the  Body. — Only  two  kinds  of  sugar  exist,  or 
are  formed  in  animals.  Grape  sugar  is  found  in  the  liver,  in 
some  of  the  veins,  and  other  organs.  In  the  disease  called 
Diabetes,  its  quantity  is  very  much  increased,  and,  in  fact,  an 
excess  of  sugar  in  the  system  is  a sign  of  serious  derangement. 

30.  Fats  in  the  Body. — The  fatty  principles,  cholesterine, 
oleine,  etc.,  exist  in  the  body  in  cells,  in  chemical  combina- 

25.  How  much  water  does  a man  consume  in  a year?  How  much  is  thrown  off  during 
the  same  time?  Explain  the  reason.  26.  Where  docs  common  salt  occur  in  the  body? 
How  many  grains  exist  in  the  body?  27.  la  what  ])arts  of  the  body  do  Carbonate  and 
Phosphate  of  Lime  occur  ? 28.  How  many  acids  and  salts  are  found  ? State  how  they 

are  formed.  29.  How  many  kinds  of  sugar  are  found  in  animals?  What  does  an  excess 
of  sugar  indicate  ? 30.  How  do  the  fats  occur  in  the  body  ? 


12 


HITCHCOCK’S  A X A T O ISr  Y 


tion  with  other  substances,  and  as  oil  drops  or  fat  globules 
not  inclosed.  These  principles  are  mostly  taken  as  food  into 
the  system,  but  they  are  most  probably  also  formed  there 
from  elements ; certainly,  the  liver  has  this  power.  One 
tenth  of  the  brain  is  composed  of  fat ; and  it  is  only  in  the 
last  stages  of  emaciation,  that  this  supply  is  exhausted. 

81.  Assiniilalioii  Necessary. — The  principles  thus  far  de- 
scribed, constitute  but  a small  proportion  of  the  animal  frame. 
Bat  the  organic,  or  coagulablc  principles,  enter  largely  into 
its  composition.  Indeed,  they  form  the  principal  source  of 
nourishment.  The  most  important  of  these  principles  (albu- 
men, fibrine,  and  caseine)  are  in  a fluid  state  in  the  body ; 
the  others  are  solid,  or  dernisolid.  Though  the  materials  for 
their  formation  must  exist  in  the  food,  yet  there  is  reason  to 
suppose  that  the  process  of  assimilation  is  necessary,  to  trans- 
form them  into  these  principles. 

32.  Albumen,  Albuminose,  Cascinc. — Coagulation  takes 
place  when  a liquid,  or  semi-liquid,  passes  into  a solid  state. 
The  white  of  an  egg  gives  a good  idea  of  one  kind  of  albumen 
(ovalbumen).  Seralbumen  exists  in  the  blood,  and  in  other 
liquids  of  the  body.  Albuminose  is  found  in  the  same  fluids, 
and  has  been,  till  of  late,  confounded  with  albumen.  It  is 
formed  in  the  upper  intestines,  but  when  it  passes  into  the 
blood,  it  becomes  mostly  albumen,  sometimes  musculine, 
fibrine,  etc.  Animal  caseine  is  found  only  in  milk,  being 
most  abundant  when  an  animal  diet  is  used.  It  contains  from 
four  to  six  per  cent,  of  phosphate  of  lime,  and  hence  the  im- 
portance of  milk  for  young  animals,  that  their  bones  may  be 
developed. 

33.  Fibrine,  liliisculinc,  Globuliiie,  Osteinc,  and  Gluten. — 
Fibrine  is  found  in  the  blood,  and  when  it  coagulates,  the  mass 
ij  fibrous,  the  process  being  called  fibrillation.  It  is  this  prin- 
ciple chiefly  that  causes  blood  to  coagulate,  the  great  importance 

Is  f:it  formed  in  tlio  body,  or  taken  in  from  tlie  food?  81,  State  the  three  most  im- 
I»ortant  orpranic  principles.  82.  Define  congnlation.  What  is  ovalbumen,  seralbumen  and 
albuminose?  In  what  is  caseine  found ? What  imjxn-tftut  ingrwlient  does  it  contain ? 
88.  Where  D fibrine  found  ? What  causes  coagulation  of  the  blood  ? What  practical  beno- 
lit  is  derived  from  coagulation  ? 


AND  PHYSIOLOGY. 


13 


of  \vliicb  in  arresting  dangerous  hemorrhages  is  well  known. 
Coagulation  appears  to  be  a vital  process,  that  is,  dependent  on 
life  for  its  development,  and  not  on  chemical  laws  only.  It  can 
be  j^revented  by  any  thing  that  destroys  life,  such  as  poisons, 
or  a temperature  too  high,  or  too  low.  Fibrine  does  not  exist 
in  the  muscles.  That  which  has  been  called  such  is  muscu- 
line,  which  is  endowed  with  the  vital  property  called  contractil- 
ity. Globuline  occurs  only  in  the  red  corpuscles  of  the  blood. 
Osteine  is  the  substance  from  Avhich  gluten  is  made,  by  the 
action  of  boiling  water,  for  gluten  does  not  naturally  exist  in 
the  body.  Osteine  is  the  essential  organic  element  in  bone. 

34.  Hemal inc. — Hema- 
tine  is  the  coloring  matter 
of  the  blood,  and  though 
iron  is  found  in  connec- 
tion Avith  it,  all  the  iron 
can  be  abstracted  without 
destroying  the  color. 

Hence,  that  can  not  de- 
pend on  the  iron.  He- 
matine  is  probably  pro- 
duced from  certain  red 
crystals,  occurring  in  the 
red  corpuscles.  A group 
of  these  crystals  is  here 
shown. 

85.  Proteine  Compounds. — All  the  organic  or  coagulable 
principles  contain  nitrogen,  or  rather,  are  composed  essen- 
tially of  oxygen,  hydrogen,  carbon  and  nitrogen.  Hence,  their 
value  as  food,  since  a greater  part  of  the  body  is  composed  of 
these  elements.  Albumen,  fibrine,  and  caseine  have  been 
termed  Proteine  Compounds,  for  they  can  easily  be  changed 

Is  fibrine  found  in  muscular  tissue  ? What  is  the  proximate  principle  of  muscular  tis- 
sue? Where  does  globuline  and  osteine  occur?  34.  What  is  the  coloring  matter  of  the 
blood?  lias  iron  any  thing  to  do  with  its  color?  What  is  the  Ilematine  produced  from  ? 
35.  What  four  simple  elements  make  up  all  the  organic  principles  ? Why  are  albumen, 
etc.,  termed  Proteine  compounds  ? — 


Fig.  3. 


H 


HITCHCOCK’S  ANA  T O M Y 


into  Proteine,  a substance,  however,  which  docs  not  exist  in 
nature,  but  results  from  the  decomposition  of  the  principles 
above  named. 


^ HISTOLOGY. 

36.  Organic  and  Inorganic  Structure.— Animals  and 
plants  have  a structure  different  from  that  of  minerals  when 
we  examine  them  with  the  microscope.  The  former  is  called 
Organic,  and  the  latter  Inorganic  Structure. 

37.  Vitality  the  Cause  of  Organization. — Vitality,  ortho 
principle  of  life,  or  the  Vital  Force,  is  the  cause  of  organi- 
zation. The  nature  of  life  is  indeed  involved  in  obscurity ; but 
its  effects  are  manifest,  and  among  them  is  organization : al- 
though some  have  maintained,  but  without  good  reason,  that 
the  vital  force  is  nothing  but  a peculiar  manifestation  of  heat, 
mechanical  force,  chemical  action,  galvanism,  etc. 

38.  Elementary  and  Primary  Tissue. — The  simplest  forms 
of  organized  structure  are  three. 

1.  Simple  Membrane. 

2.  Simple  Fiber. 

3.  Cells. 

These  organic  forms  physiologists  denominate  Elementary 
Tissue.  When  united,  they  form  Primary  Tissue. 

39.  Histology;  Proportion  of  Tissues  in  the  Body. — 
Histology  is  the  science  of  Tissues.  Tissue  forms  nearly  the 
whole  of  the  solid  portions  of  the  body.  By  means  of  the  mi- 
croscope, they  have  been  examined  with  great  care,  and  de- 
scribed. 

40.  Fluids  of  the  System;  Ilygrology. — Before  entering 
upon  a description  of  the  tissues,  it  seems  desirable,  at  least, 
to  enumerate  the  different  fluids  found  in  the  system,  though  a 

80.  Define  organic  and  inor<xanic  stmcliiro.  37.  Give  the  cause  of  organization. 
8S,  State  tlie  three  simple  forms  of  organizcal  structure.  What  is  Elementary  Tissue? 
AVdiat  Is  Primary  Tissue ? 89  Define  Histology.  What  forms  the  solid  parts  of  the 

body  ? 40.  Wliat  is  Ilygrology  ? 


AND  PHYSIOLOGY. 


15 


fuller  description  of  them  will  be  given  further  on.  These 
fluids  contain  the  elements  of  the  tissues.  That  part  of 
anatomy  which  treats  of  them  is  called  Hygrology. 

41.  Lymph. — Lymph,  a transparent,  coagulable  fluid,  in 
the  lymphatics,  emptying  into  the  blood. 

42.  Chyle. — Chyle,  a white,  coagulable  fluid,  derived  from 
the  food  in  the  intestines,  and  conveyed  to  the  blood. 

43.  Blood. — Blood,  in  the  veins  and  arteries,  from  which 
nearly  all  the  parts  of  the  system  are  sustained,  a coagulable 
fluid,  with  an  alkaline  reaction. 

44.  Scrum. — Serous  secretions,  fluids  found  on  various 
serous  membranes,  as  the  pleura,  peritonaeum,  pericardium, 
and  membranes  of  the  brain  and  ear. 

45.  Transudations. — Transudations,  vapor  from  the  lungs, 
and  sometimes  from  the  skin ; also,  fluids  in  some  of  the  tis- 
sues, more  especially  in  certain  diseases,  as  dropsy  in  the 
head,  chest,  and  abdomen,  certain  sweats  and  discharges  in 
cholera,  etc. 

46.  Exudations. — Exudations,  ‘ ^ any  organizable  fluid 
spontaneously  separated  from  the  blood  vessels,  without  rupt- 
ure of  their  walls,”  chiefly  occurring  in  inflammations,  and 
wLerever  new  material  is  required  for  repair  of  the  system. 
The  pus  of  wounds  and  sores  is  an  example  of  exudation. 

47.  Mucus. — Mucus,  a viscid  mass  capable  of  being  drawn 
into  threads,  secreted  from  the  mucous  membrane,  but  differ- 
ing in  different  parts. 

48.  Gastric  Juice  and  Pepsin. — Gastric  fluid,  a fluid 
secreted  by  the  stomach,  containing  a substance  called  Pepsin, 
which  aids  in  digestion.  It  contains  a little  free  chlorohydric 
and  lactic  acids. 


41.  What  is  Lymph  and  what  becomes  of  it?  42.  Define  Chyle  and  state  what  be- 
comes of  it.  43,  Define  the  blood.  44.  What  membranes  secrete  the  serum  ? 45.  Define 
transudations.  In  what  diseases  do  they  occur  ? 46.  What  are  exudations  ? When  are 
they  serviceable  ? 47.  What  does  the  mucous  membrane  secrete  ? 4S.  Define  and  de- 
scribe the  secretions  of  the  stomach. 


IG 


II  I T C II  <;  o C K ’ S ANATOMY 


49.  Intestinal  Fluid. — The  intestinal  fluid,  a colorless, 
tenacious  fluid,  with  strong  alkaline  reaction,  whose  function 
is  to  assist  in  digestion.  Secreted  by  the  epithelial  cells  of 
the  intestinal  follicles. 


Fio.  4. 


O 0 o O 
O W O oOOOf* 


Or?,.Om 

QOjO 


i Oo 


o o 


' o 


^ oO  ^ 

o oO> 


^ " 


o C 


50.  Milk.— Milk,  a 
glandular  secretion, 
showing  under  the  mi- 
croscope an  immense 
number  of  fat  globules, 
suspended  in  a clear 
fluid,  as  in  fig.  4. 

51.  Saliva . — Saliva, 
a secretion  chiefly  from 
the  parotid  and  submax- 
illary gland  into  the 
mouth,  to  assist  in  diges- 
tion. 


52.  Bile. — Bile,  a 

greenish  or  brownish 

bitter  fluid,  secreted  by  the  liver  to  assist  in  digestion. 


53.  Pancreatic  Jtiicc.^ — -Pancreatic  fluid,  a colorless,  taste- 
less, but  somewhat  alkaline  fluid,  secreted  by  the  pancreas  to 
aid  in  digestion. 

54.  Urine, — Urine,  secreted  by  the  kidneys. 


55.  Tears. — Lachrymal  fluid  for  lubricating  the  eyeballs, 
secreted  by  the  lachrymal  gland. 

56.  Oil  and  AVax. — Sebaceous  secretions,  fatty  fluids  thrown 
out  by  what  are  called  the  sebaceous  follicles  of  the  skin,  to 
keep  it  moist. 

57.  Sweat. — Perspiration,  or  sweat,  a colorless,  watery 

40.  Whut  is  tlio  Intestinal  fluid  ? 50.  How  does  milk  appear  under  the  microscope? 
.51.  What  is  the  origin  and  use  of  saliva?  52.  State  the  secretion  of  the  liver.  53.  &c, 
Describe  I’ancreatic  Juice.  Urine.  Tears.  Oil  and  Wax.  57.  From  what  glands  is 
sweat  j)roduoed  ? 


AND  r II  Y S I O L O G Y . 


17 


fluid,  with  a saltish  taste,  and  having  odor,  secreted  from  the 
perspiratory  glands. 

Elementary  Tissues. 

58.  Simple,  or  Basement  Membrane.— 1.  Simple  Mem- 
brane, This  is  usually  a structureless  layer  of  coagulated 
albumen,  often  not  more  than  20000th  of  an  inch  thick.  It 
forms  the  walls  of  all  cells,  and  is  also  spread  out,  as  an  in- 
ferior layer  of  the  skin  and  mucous  membrane,  and  is  then 
called  basement  membrane.  It  is  the  most  simple  of  all  the 
tissues,  yet  it  is  the  agent  of  secretion,  and  sometimes  of  ab- 
sorption, and  these  Professor  Peaslee  considers  as  its  vital 
properties,  though  of  a low  grade. 

59.  Imbibition. — Simple  membi-ane  also  possesses  the  re- 
markable property  of  allowing  fluids  to  pass  through  it  when 
it  is  placed  between  two  fluids  ; the  effect  depending  in  part 
upon  the  electro-chemical  relations  of  the  substances,  but  not, 
as  generally  supposed,  on  the  difference  of  specific  gravity 
of  the  liquids.  This  is  called  endosmose  and  exosmose,  or 
Imbibition,  and  is  the  principal  means  by  which  fluids  are 
made  to  pass  from  one  part  of  the  system  to  another,  where 
no  distinct  vessels  are  provided  for  that  purpose. 

60.  Simple  Fiber. — 2.  Simple  Fiber,  This  consists  es- 
sentially of  threads  of  coagulated 
fibrine,  whose  average  diameter  is 
about  8 smooth  of  an  inch  thick.  It 
does  not  appear  to  be  a permanent 
constituent  of  the  body,  but  only 
a basis  for  the  development  of  the 
more  complicated  tissues.  A good 
example  of  the  simple  fiber  may 
be  seen  in  the  membrane  lining 
the  inside  of  an  egg  shell,  as  in 
Fig.  5. 


Fig.  5. 


58.  What  is  simpl©  membrane  ? IIow  thick  ? Where  is  it  found  ? What  other  name 
is  given  to  it?  59.  Describe  Imbibition.  What  purpose  does  it  effect?  60.  Dcsoribo 
simple  fiber.  Its  size.  Where  best  seen  ? 


18 


HITCHCOCK’S  ANATOMY 


61.  Shape  of  Cells.— 3.  Cells.  Theso  aie  merely  mem- 
branous bags,  or  vesicles,  from  i to  ou'ootb  of  an  inch  in 
diameter,  filled  with  some  kind  of  liquid,  or  solid  substance. 
When  free,  the  form  is  spherical,  or  spheroidal,  as  in  Fig.  6. 
But,  as  they  press  against  one  another,  they  are  brought  into 
a polyhedral  form,  as  in  Fig.  7,  showing  a group  of  fat  ve- 
sicles. 


Fig.  6. 


Fig.  7. 


62.  Contents  of  Cells;  Granules;  Nucleus  anil  Nucleo- 
lus.— The  fluid  of  cells  is  transparent,  except  in  the  case  of 
blood.  In  it  there  generally  float  an  immense  number  of  gra- 
nules, having  no  investing  membrane,  but  sometimes  they  are 
thus  invested.  Each  cell  has  also  a nucleus  and  a nucleolus  ; 
the  first  being  a globular,  or  lenticular  body,  from  e o'o  oth  to 
g o‘ooth  of  an  inch  in  diameter,  attached  to,  or  imbedded  in  the 
wall  of  the  cell,  though  some  are  free.  The  nucleolus  is  a 
granule  within  the  nucleus.  Both  are  shown,  as  well  as  the 
common  granules,  in  Fig.  6. 

63.  Appendages  of  Cells. — Sometimes  cells  have  a sort  of 
tail  attached  to  them,  and  are  hence  called  caudate,  as  in 
Fig.  8.  Sometimes,  too,  they  are  stellate,  as  in  Fig.  9,  show- 
ing the  pigment  cells  of  a frog’s  foot. 

Cl.  Define  cells.  What  is  the  original  form  of  them  ? IIow  do  they  acquire  the  poly- 
hedral form?  C2.  Explain  nucleus,  nucleolus  and  cell  wall.  63.  What  arc  the  appendages 
of  cells? 


64.  Cytogenesis . — The  cell  is  the  most  important  of  the  ele- 
mentary tissues,  for,  by  its  multiplication,  most  of  the  other 


64.  Give  the  process  by  which  cells  increase  and  form  tissnei. 


20 


HITCHCOCK’S  A X A T O ]Sr  Y 


Fig.  10. 


tissues  in  animals  and  vegetables  are  made  up.  Tliis  is  called 
cytogenesis.  The  increase  usually  takes  place  by  duplicative 
subdivision,  which  is  shown  on  Fig.  10.  The  cell  a a first 
becomes  elongated,  as  at  6,  and  then  it  divides  at  c c.  The 
subdivision  going  on  will  give  an  increase  in  rapid  ratio — 2, 
4,  8,  16,  32,  etc.  Fig.  11  shows  an  example  of  this  division, 

A,  B,  C,  D,  in  its  earlier 
stages,  and  E,  F,  G,  II,  in 
its  more  advanced  condition. 
Sometimes  cells  multiply  by 
the  development  of  new  cells 
in  the  interior.  In  this  case 
the  nucleus  subdivides  into 
two  or  more  portions,  which 
at  length  fill  the  original  cell, 
as  is  shown  in  Fig.  12.  Some- 
times cells  are  formed  by  the 


expansion 


of  homogeneous 


Fig.  11. 

A B c D 


granules  into  cells  ; or  they  are  even  produced  in  the  midst  of 
a formative  fluid  (called  a blastema),  poured  out  from  the  blood. 

Hoscrlbo  tho  modo  of  foruitttion  as  Illustrated  in  Figures  11  and  12.  What  is  the 
Blasteinu? 


AND  PHYSIOLOGY. 


21 


65.  It  is  in  these 
Avajs  that  most  of  the 
tissues  of  the  body  are 
built  up,  and  the  animal 
enlarges  to  its  full  size. 

It  has  been  maintained 
that  all  the  tissues  orig- 
inate in  cell  develop- 
ment. But,  in  some 
cases,  simple  fibers  and 
membranes  seem  to  be 
formed  directly  out  of 
an  organizable  s u b - 
stance,  without  the  in- 
tervention of  cells. 

66.  Vital  Force  of 
Cells;  Chemical  Trans- 
formations; Vitalization  of  the  Cells;  Change  of  Form; 
Development  of  Nerve  Force.— The  multiplication  of  cells 
is  one  of  the  manifestations  of  the  vital  force  inherent  in  them. 
Another  is  the  chemical  transformations  exerted  upon  the  con- 
tents of  the  cell  in  some  instances,  whereby  new  products 
are  generated.  Another  is  the  vitalization  of  a portion  of 
the  cell  contents,  whereby  they  are  able  to  produce  new 
cells.  Another  is  permanent  changes  of  form  in  connection 
with  growth.  Another  is  temporary  changes  of  form,  ac- 
companied with  sensible  motion,  as  in  the  oscillatory  move- 
ments of  the  leaves  of  Hedysarum  gyrans,  and  the  fold- 
ing of  the  leaves  of  the  Mimosas  upon  touch.  Finally,  the 
development  of  nerve  force  from  cells,  by  which  all  the  bodily 
operations  may  be  modified,  and  which  is  intimately  connected 
with  mental  agency. 

67.  Periods  in  the  Life  of  the  Cells. — In  cell  life  there  is  a 


Fig.  12. 


65.  Show  how  the  tissues  of  the  body  are  made  up.  66.  Mention  the  different  changes 
which  cells  undergo. 


TI  I T C II  C O C K ’ S ANATOMY 


O') 

period  of  augmentation,  another  of  perfection,  another  of  de- 
cline, and,  finally,  one  of  cessation.  So  long  as  vitality  can  use 
chemical  and  physical  agencies  for  building  up  the  system, 
they  tend  to  its  preservation,  but,  when  life  ceases,  they  tend 
to  its  destruction,  not,  as  is  generally  thought,  because  the 
vital  principle  has  not  the  power  of  resisting  these  agencies, 
but  because  it  can  no  longer  turn  them  into  the  channel  for  pre- 
serving the  system. 

PRIMARY  TISSUES. 

The  chief  mass  of  the  animal  system  is  made  up  of  the  ele- 
mentary forms  that  have  been  described,  variously  combined 
so  as  to  form  plexuses  and  webs,  which  are  called  primary 
tissues  by  some,  and  compound  tissues  by  others.  They  are 
differently  classified  by  different  writers.  The  arrangement 
Avhich  follows  is  that  of  Professor  W.  B.  Carpenter : 

1.  Simple  Fibrous  Tissues. 

68.  White  and  Yellow  Fibrous  Tissues.— This  embraces 
the  white  and  yellow  fibrous  tissues,  as  well  as  the  areolar  or 
connective  tissue  of  other  writers.  The  white  fibers  are  from 
^Vooth  to  the  2 0^-0  6 A of  an  inch  in  diameter,  and  form  the 
tendons,  ligaments,  and  fibrous  membranes.  (Fig.  13.)  The 


Fio  13  Fig.  14 


t}l.  Give  the  four  difTerent  periods  in  the  life  of  cells.  68,  Give  the  size  of  the  fibers 
of  while  and  yellow  fibrous  tissues. 


AND  PHYSIOLOGY. 


23 


yellow  fibers  are  about  o^h  of  an  inch  in  diameter  and  form 
a part  of  the  larynx,  and  the  middle  coat  of  the  arteries. 

69.  Areolar  Tissue. — The  areolar  tissue  consists  of  fibers 
of  white  and  yellow  tissue  interwoven,  so  as  to  leave  irregular 
spaces,  or  areolae,  between  them.  This  tissue  originates  from 
cells,  as  is  shown  in  Fig.  16.  The  areolar  tissue  is  more  widely 
diffused  than  any  other  in  the  body,  so  that  if  it  were  possi- 
ble to  remove  all  but  this  one,  the  form  of  the  part  would  be 
preserved.  It  surrounds  all  the  arteries  and  veins,  the  nerves, 
muscles  and  internal  organs ; and  it  forms  one  of  the  layers  of 
the  skin  and  mucous  membrane. 


Fig  15. 


Fig.  16. 


2.  The  Fibro-Cellular  Membranes. 

70.  One  of  the  layers  of  the  skin,  of  the  mucous  membrane, 
and  the  serous  and  synovial  coat  that  lines  the  shut  cavities  of 
the  body,  is  composed  of  interwoven  fibers  of  simple  basement 
membrane  , and  of  one  or  more  layers  of  cells  upon  the  free 


69.  What  is  the  composition  of  areolar  tissue?  What  of  its  abundance  in  the  body? 
Where  is  it  principally  found  ? 70.  Describe  the  fibro-cellular  membrane. 

2 


24 


II  ] T O If  C OCR’S  \ N A T O V 


surface.  This  is  tlic  fibro-ccllular  membrane  or  tissue.  Its 
position  and  character  will  be  l)etter  understood  when  the  parts 
above  referred  to  have  been  described  in  subseej^uent  sections. 


3.  Cellular  Tissues. 

71.  Fat  and  Cartilage.  — These  embrace  the  adipose  tis- 
sues, Fig.  17,  and  the  cartilaginous,  Fig  18.  The  first  is  the 
usual  form  of  fat,  wherever  it  occurs  in  the  system.  It  retains 
the  pure  form  of  the  primitive  cells.  In  cartilage,  also,  these 
cells  sometimes  exist  alone,  but  more  frequently  they  are  inter- 
woven with  fibers,  as  seen  by  the  figures. 

4.  Sclerous  Tissues. 

72.  Bones  and  Tectli. — These  constitute  the  bones  and 
teeth,  and  are  composed  of  an  animal  basis  of  fibers  and  cells  ce- 
mented together  by  phosphate  and  carbonate  of  lime.  Fig.  19, 
which  is  a transverse  section  of  one  of  the  bones  of  the  arm, 
will  give  an  idea  of  the  arrangement  of  the  animal  matter, 
tlie  earthy  part  having  been  dissolved  by  acid.  Fig.  20  shows 
a transverse  section  of  tlie  shoulder  blade,  exhibiting:  tlie  dark 
spaces  called  laciiiun. 

71.  Di’.scribo  fat  uiul  carl.ila^o.  7'2.  Wliat  is  the  composition  of  tlie  bones  and  tho 
teeth  ? 73.  What  are  tho  cui»illarie8  and  absorbents?  Give  tho  size  of  the  capillaiios. 


AND  PHYSIOLOGY. 


25 


Fig.  19 


73.  Capillaries  and  kig  20 

Absorbents.  — These 
form  those  minute  blood 
vessels  called  capillaries, 
and  others  called  lym- 
phatics or  absorbent  ves- 
sels, which  exist  in  every 
part  of  the  body,  and 
are  distinct  from,  al- 
though connected  with, 
the  arteries  and  veins. 

The  capillaries  c 0 n - 
nccting  these  are  from 
2Jooth  to  37’ooth  of 


Tr  T T C IT  C O C K ’ S A N A T O Y 


Fig.  21. 


an  inch  in  diameter,  less  often  than  tlie  Idood  cor- 
puscles. In  some  other  animals  they  are  larger, 
as  may  be  seen  in  the  capillary  plexus  of  a frog’s 
foot,  shown  in  Fig.  9.  The  lymphatics  abound 
with  valves,  may  be  seen  in  Fig.  21. 

G.  Muscular  Tissue. 

ul.  M ripe  (I  and  iSnmolli  Muscle. — This  tissue 
is  made  up  of  two  forms  of  fiber,  the  striped  and 
unstriped.  The  stripes  in  the  first  form  run  both 
transversely  and  longitudinally,  as  may  be  seen 
Fig.  22. 


in  Fig.  22.  When  separated  longitudinally,  the 
fibrillas  have  a beaded  appearance,  each  bead 
being  in  fact  a cell,  as  is  here  represented  in 
Fig  23,  which  shows  the  cells  a when  most 
relaxed,  and  b when  most  contracted.  Muscular 
fiber  is  capable  also  of  being  divided  crosswise 
in  the  direction  of  the  transverse  striae  into  discs, 
as  seen  in  Fig.  24.  Both  the  striated  (striped) 
and  non-striated  muscles  originate  in  cells. 
Figs.  25  and  26  show  their  development. 

75.  Myotility. — The  grand  peculiarity  of 
muscular  tissue  is  its  power  of  contraction — a 
phenomenon  as  mysterious  and  wonderful  as 
any  thing  in  nature.  This  is  called  myotility 
or  contractility. 


Wliutdo  (lie  lytiiplintics  :iboim(l  in?  74.  Distiiifruisii  bctAvocii  tlio  strii)0(l  and  tho 
misti  iiKid  imiHcuIar  fiber.  Clive  the  reason  of  the  dillerence  between  a and  l>  in  Fig.  23. 
Vo.  Define  luyctillty. 


AND  rilYSIOLOGY. 


27 


Fia  24. 


Fig.  25.  Fig.  26. 


76.  The  Chemical  Composition  of  Muscle. — The  chem- 
ical composition  of  the  muscular  tissue  is  almost  exactly  the 
same  as  that  of  blood,  as  the  following  analysis  will  show  : 

Blood.  M little. 


Carbon 51.83  51.95 

Hydrogen 7.6Y  ’7.n 

Nitrogen 15.01  15.07 

Oxygen 21.36  21.39 

Ashes 4.23  4.52 


100.00  100.00 


76.  State  the  chemical  composition  of  muscle. 


28 


HITCHCOCK’S  ANATOMY 


7.  Nervous  Tissue. 

77.  Nervous  Tissue;  Tubular  Cells. — This,  like  some  of 
the  other  tissues,  is  composed  of  cells,  fibers  and  tubes,  but  it  is 
distinguished  from  all  others  by  its  vital  endowments.  In  the 
ordinary  nerve  trunks  the  tissue  is  the  fibrous  or  tubular,  as  is 
shown  in  fig.  27,  A,  B,  and  C.  In  C some  of  the  original  cel  Is 
are  shown. 

Fro.  27. 


78.  Vesi- 
cular Cells; 

Granular 
Cell  s. — In 
those  nervous 
masses  called 
ganglia,  w e 
find,  in  addi- 
tion to  the 
fibers,  a sub- 
stance made 
up  of  vesicles 
or  cells,  as  is 
shown  in  the  ganglion  of  a mouse  on  fig.  28. 


77.  How  itj  ncM-vous  tissue  to  bo  distinguished  from  all  other  tissues?  78.  Describe 
the  vesicular  cells. 


AND  PHYSIOLOGY. 


29 


Another  primary  element  of  the  nervous  system  is  com- 
posed of  nucleated  cells,  containing  a finely  granulated  sub- 
stance. These  sometimes  have  processes  which  give  them  a 
caudate  or  stellate  form,  as  in  Fig.  29. 


Fia.  29. 


79.  All  Organ.  The  System,— Such  are  the  tissues  which, 
combined  in  various  proportions,  make  up  the  organs  of  the 
human  body.  And  by  the  term  organ  we  mean  a part  usually 
composed  of  several  tissues  adapted  to  certain  functions.  And 
though  harmoniously  united  into  a single  system,  that  is,  the 
body,  the  anatomist  can  dissect  and  describe  them  separately. 
In  this  work  the  following  order  wdll  be  adopted : 

1.  Osteology^  or  an  account  of  the  Bones  or  framework  of 
the  system. 

2.  Myology^  an  account  of  the  Muscles  or  the  moving  pow- 
ers of  the  system. 

3.  SplayicJiTiology^  or  the  Nutritive  Organs. 

4.  Angiology^  an  account  of  the  Circulating  System  of  the 
arteries  and  veins. 


, Define  an  organ.  What  is  the  system  ? What  is  Osteology  ? Myology  ? etc. 


30 


II  I T C II  C O O K ’ S AX  A T O *M  V 


5.  Pneumonologijj  or  an  account  of  the  Respiratory,  Vocal, 
and  Calorific  Organs. 

6.  Ichorolofjy^  or  the  Lymphatic  and  Secreting  System. 

7.  Neurology^  or  the  history  of  the  Nervous  System,  the 
vivifying  power. 

8.  The  Inlets  of  the  soul,  or  the  Senses. 

9.  Religious  teachings  of  the  subject. 


CHAPTER  FIRST. 


THE  FRAMEWORK  OF  THE  SYSTEM.— OSTEOLOGY,  OR 
A DESCRIPTION  OF  THE  BONES. 


DEFINITIONS  AND  DESCRIPTIONS. 

80.  Chemical  Composition  of  Bone. — The  Bones  of  all 
vertebrate  animals  are  principally  composed  of  the  Phosphate 
and  Carbonate  of  Lime,  and,  with  the  exception  of  the  Teeth 
and  articular  extremities,  are  closely  covered  by  a firm  mem- 
brane called  the  Periosteum.  By  chemical  analysis  the  com- 
position is  as  follows : 

Organic  substance  (Osteine  or  Cartilage)  33.00 


Phosphate  of  Lime 57.00 

Carbonate  of  Lime. 8.00 

Fluorid  of  Calcium 1.00 

Phosphate  of  Magnesia 1.00 


100.00 

81.  Cartilage  and  Salts  of  lime  shown. — Hence  we  see 
that  the  principal  constituents  of  bone  are  the  salts  of  Lime 
and  Cartilage.  The  former  can  be  easily  obtained  by  burning 
the  bone  a while  in  a hot  fire,  which  appears  like  a white 
powder  when  crushed.  The  Cartilage  is  obtained  by  im- 
mersing it  for  a considerable  time  in  a dilute  acid,  when  we 
have  the  form  of  the  bone  perfectly  retained,  although  nothing 
is  left  but  cartilage.  Its  elastic  character  may  be  inferred 

80.  What  are  the  principal  ingredients  of  bones?  Where  is  the  Periosteum  found? 
Give  the  chemical  analysis.  81.  How  can  the  earthy  ingredients  be  shown?  The  car- 


32 


HITCHCOCK’S  ANATO^FY 


frogi  Fig.  30,  Avliicli  is  a human 
Fibula  tied  in  a knot  after  hav- 
ing been  immersed  for  some 
time  in  muriatic  acid. 

82.  Mechanical  fonstnic- 
tion  of  Bones. — As  a general 
law  the  extremities  are  the 
largest,  and  the  bodies  or  shafts 
are  smooth  and  of  a uniform 
surface.  They  are  in  most 
cases  so  constructed  as  to  give 
the  greatest  strength  and  sup- 
port, and  at  the  same  time  fur- 
nish as  little  weight  as  possible. 
Hence  the  long  bones  are  most- 
ly hollow,  or  have  an  arched 
form,  while  the  flat  bones  are 
portions  of  a circle  or  sphere.  In  the  face  also  the  bones  are 
not  all  solid,  but  some  of  them  contain  large  cavities,  so  that 
firm  attachment  may  be  given  to  the  muscles,  and  protection 
to  the  more  delicate  parts. 

83.  Average  Weight  of  adult  Skeleton.— The  weight  of 
the  skeleton  is  as  10.5  : 100,  or  about  one  tenth  the  weight 
of  the  whole  body.  And  since  the  average  weight  of  an  adult 
man  is  136  pounds,  the  weight  of  an  adult  skeleton  is  about 
13.5  pounds. 

84.  Strength  of  Bones. — The  power  of  the  human  bones 
as  levers  when  compared  with  different  substances  is  remark- 
able, as  is  seen  by  the  following  table. 


Freestone  (sandstone) 1. 

Lead 6.5 

Elm  and  Ash  (wood) 8.5 

Box,  Yew,  and  Oak 11.  ^ 

Human  Bone 22. 


Fig.  30. 


82.  Which  part  of  the  bones  is  penerally  tlio  largest?  Why  are  many  of  the  bones 
hollow  or  partially  so?  88.  Give  the  wclpht  of  the  human  skeleton.  What  is  its  pro- 
yortion  to  that  of  the  whole  body  ? 84.  Give  the  comparative  strength  of  the  bones. 


AND  rilYSIOLOGY. 


33 


That  is,  bone  when  used  as  a lever  is  22  times  as  strong  as 
Sandstone,  3!  times  as  strong  as  Lead,  nearly  2f  times  as 
strong  as  Elm  and  Ash,  and  2 times  as  strong  as  Box,  Yew, 
and  Oak  timber. 

85.  Microscopic  Structure  of  Bone. 

Haversian  Canals.  — Examined  by 
the  microscope  the  bones  are  found  to 
be  made  up  of  plates  or  layers  for 
the  most  part,  arranged  concentrically 
in  the  long  bones,  and  in  parallel 
layers  in  the  flat  ones.  These  are 
traversed  in  all  directions,  and  espe- 
cially in  their  long  diameters,  by 
minute  tubes  or  vessels  called  Ha- 
versian canals,  which  are  also  en- 
circled by  several  laminse  or  plates 
besides  those  following  the  general 
outline  of  the  bone.  Fig.  31.  These 
canals  have  a diameter  varying  from 
T2V0  24  ofh  of  an  inch,  while  the 
accompanying  lamellae  show  a thick- 
ness of  ■co^^Trt'^  inch.  They  layer.  2 and  3,  inner  layers, 

sometimes  contain  a capillary  vessel, 

but  more  usually  carry  only  the  nutritive  and  watery  portion 
of  the  blood. 

8G.  lacunsB,  Canal iculi. — Besides  these  canals  we  find  a 
smaller  set  of  vessels  or  cells  located  directly  in  the  substance 
of  the  concentric  lamellae,  called  Lacunae  or  Bone  Corpuscles, 
which  average  y oVo^h  of  an  inch  in  length,  and  carry  the  fluid 
which  nourishes  the  bone.  These  are  of  a black  appearance, 
of  an  oval  form,  and  with  rays  divergent  in  all  directions,  as 


Fig.  31. 


Transverse  section  of  bone 

■mofrnifia/-!  1 i <n  Yin  1 


85.  How  are  the  particles  of  matter  arranged  in  the  long  bones  ? How  in  the  flat 
ones?  Describe  the  Haversian  canals.  Their  diameter.  What  vessel  does  each  one 
contain  and  what  is  the  purpose  of  that  vessel?  86.  What  are  the  Lacunie  or  Bone 
Corpuscles  ? 


34 


HITCHCOCK’S  ANATOMY 


seen  in  Fig.  32.  These 
rays  are  minute  canals, 
and  nearly  all  of  them 
anastomose,  or  have  com- 
munication with  each  other. 
They  are  called  Canaliculi, 
or  Bone  Pores,  and  mea- 
sure 3oiT7oth  of  an  inch 
in  diameter. 

87.  Ultimate  Granules. — The  ultimate  histological  ele- 
ment, or  the  smallest  element  of  bones  as  yet 
discovered,  is  made  up  of  pale  oval  granules, 
about  0 oVotU  of  an  inch  in  diameter.  These 
granules  constitute  all  the  substance  of  the  bone 
except  the  minute  vessels  already  mentioned. 

88.  Hence  the  microscopic  elements  of  bone  are  four  : 

1.  Haversian  Canals. 

2.  Lacunae  or  Bone  Corpuscles. 

3.  Canaliculi  or  Bone  Pores. 

4.  Ultimate  Granules. 

89.  Periosteum. — In  all  parts  of  the  body,  both  solid  and 
fluid,  we  find  that  nature  has  made  ample  protection  by 
providing  for  nearly  every  organ  a firm  membranous  sheath. 
This  not  only  serves  as  a protection  and  support,  but  in 
many  cases  a means  of  nutriment.  Upon  the  bones  ac- 
cordingly we  find  a very  firm  whitish  yellow  membrane 
closely  attached  to  them  in  most  places,  and  vjery  smooth, 
called  the  Periosteum.  This  occurs  on  every  part  of  every 
bone,  except  at  the  articulations,  and  upon  the  crowns  of  the 
teeth.  It  is,  Avhen  healthy,  perfectly  insensible,  and  contains 
the  vessels  which  ramify  into  the  bones,  being  in  fact  the 

Wliat  arc  the  Bono  Pores  or  Canaliculi?  87.  What  is  the  smallest  or  ultimate  element 
of  bones  ? 88.  Give  the  four  microscopic  elements  of  bone.  89.  What  is  the  color  of 

the  Periosteum?  On  what  part  of  the  bones  is  it  wanting?  W^hat  two  important 
purposes  docs  it  subserve? 


Fig.  33. 


Fig.  32. 


Lacunae  of  Bone,  o,  central  portion, 
canaliculi  or  Bone  Pores. 


AND  PHYSIOLOGY. 


nutrient  membrane  of  the  bones.  Besides 
this  function,  the  periosteum  serves  as  a 
point  of  attachment  for  the  ligaments  and 
tendons,  in  as  much  as  they  could  not  find 
firm  attachments  on  the  bone  itself. 

Remark. — Discuses  ci  Periosteum. — In 
the  diseases  known  as  Felon  and  Fever  Sore, 
the  Periosteum  is  the  seat  of  the  inflamma- 
tion, although,  if  it  be  not  soon  checked,  the 
bone  itself  becomes  implicated. 

90.  Processes  of  Bones. — The  bones  of 
animals  are  not  constructed  after  any  regu- 
lar geometrical  form  or  curve,  but  are  mod- 
eled upon  the  plan  which  may  secure  the 

, ^ 1 r*  ‘Ti  (*  • Periosteum  of  a hume- 

greatest  firmness  and  tacility  ot  motion,  rus  partly  taken  oif. 
Accordingly  we  find  their  surfaces  quite 
uneven,  presenting  in  many  places  prominent  projections, 
which  serve  as  a firm  point  of  attaclu5»ent  for  muscles  and 
ligaments.  These  are  called  Processes,  and  are  generally  ^ 
found  near  the  extremities  of  bones,  and  are  largest  where 
the  greatest  strength  of  muscle  and  ligament  is  required^^as 
showm  in  the  bones  of  the  lower  extremities. 

I 

91.  Nutritious  Foramina. — Upon  nearly  all  the  bones 4f 

the  body  may  be  found  small  tubular  openings^  'v^hich,  after 
extending  for  a short  distance  into  the  bone,'  give 

off  the  minute  capillary  vessels  which  circulate  through  the 
larger  Haversian  canals.  They  are  called  nutritious  fora- 
mina, or  openings,  since  they  convey  nutriment  to  a large 
portion  of  the  bone. 

92.  Four  Classes  of  Bones. — Bones  are  divided  according 
to  their  shape  into  four  classes : long,  flat,  short,  and  irregu- 

What  is  the  seat  of  Felon  and  Fever  Sore?  90.  What  is  the  general  outline  of  bones? 

W'hat  are  Processes?  91.  What  are  the  nutritious  foramina,  and  with  what  vessels  do 
they  communicate  ? Their  use  ? 92.  Give  the  four  classes  of  bones,  and  give  examples 
of  the  long  ones. 


HITCHCOCK’S  ANATOMY 


lar.  The  long  ones  are  mostly  found  in  the  extremities,  and 
consist  of  a hollow  shaft  with  enlarged  and  partially  smoothed 
extremities,  and  sometimes  a rough  or  elevated  portion  along 
their  central  portions.  Those  which  belong  to  this  class,  arc 
the  Clavicle,  Humerus,  Radius,  Ulna,  Femur,  Tibia,  Meta- 
tarsus, and  Metacarpus,  Phalanges  and  Ribs. 

93.  Short  Bones. — The  Short  bones  arc  irregularly  cuboid 
in  form,  and  are  found  in  those  places  where  there  is  but 
little  motion  of  the  part.  They  are  the  Vertebrne,  Coccyx, 
Carpus  and  Tarsus,  Patella,  and  Sesamoid  bones. 

94.  Flat  Bones. — The  Flat  bones  are  arranged  to  enclose 
and  protect  cavities.  Those  of  the  head  are  made  of  two 
layers  of  bony  matter,  with  an  intervening  porous  substance 
called  the  Dipl66.  These  are  the  Occipital,  Parietal,  Frontal, 
Nasal,  Lachrymal,  Vomer,  Sternum,  Scapula,  and  the  Os 
Innominatum. 

95.  Irregular  Bones. — The  Irregular  bones  are  those 
which  belong  to  neither  of  the  preceding  classes,  and  have 
no  typical  form.  They  are  the  Temporal,  Sphenoid,  Eth- 
moid, Superior  and  Inferior  Maxillary,  Palate,  Turbinated, 
Hyoid,  and  Sacrum. 

96.  Development  of  Bone  from  Cartilage. — The  early 
condition  of  bone  is  that  of  cartilage,  which  has  the  general 
outline  of  the  bone,  and  from  the  subsequent  process  may 
be  called  the  mould  of  the  bone.  Very  early  in  life,  and 
even  before  birth,  bony  matter  begins  to  be  deposited  in  the 
cells  of  the  matrix  (cartilage)  until  at  length,  the  whole 
becomes  solid,  as  it  is  found  in  adults.  At  birth  the  only 
bone  which  is  completely  ossified  is  that  portion  of  the  tem- 
poral called  the  petrous,  which  contains  the  organ  of  hear- 
ing, while  all  the  bones  are  not  completely  ossified  be- 
fore the  12th  year  of  life.  This  process  of  hardening,  or  os- 

93.  Wliat  is  the  general  outline  of  short  bones  and  where  are  they  found  ? Give  ex- 
amples. 94.  Give  the  use  of  the  flat  bones.  ]']xaini)les  also.  95.  What  are  some  of 
the  irregular  bones?  90.  What  Is  the  first  stage  of  bone?  When  is  the  process  of  ossifi- 
cation coinj)lete  ? What  bones  are  the  first  that  become  ossified  ? 


AND  PHYSIOLOGY. 


^ es 


es»  03  c=>  «:»  < 


sification,  begins  at  Fig.  35. 

certain  points,  and 
continues  until  the 
whole  is  completed 
as  is  seen  in  the 
Fig.  36.  In  some  of 
these  bones  there  is 
but  one  of  these 
centers,  or  points, 
where  ossification 
commences,  while  in 
the  Sphenoid  there 
are  12. 

97.  Number  of 
Bones. — The  num- 
ber of  bones  in  the 
human  system  is 
reckoned  differently 
by  different  anatom- 
ists since  many  of 
the  bones  are  well 
exhibited  only  in 
hard  working  or 
well  developed  mus- 
cular subjects.  The 
number  246  will  be 
given  in  this  book 
as  taken  from  Eras- 
mus Wilson,  whose 
work  on  Anatomy  is 
adopted  as  the  text 
book  in  nearly  all  the  medical  schools  of  this  country.  This  in- 
cludes the  teeth,  and  sesamoid  bones,  of  which  the  latter  are  not 
constant  in  every  individual.  They  are  summed  up  as  follows : 


Section  of  cartilage  near  the  point  of  ossification. 
1,  ordinary  appearance  of  cartilage.  2 and  8,  more  ad- 
vanced stages  of  ossification.  1',  2'  and  3'  portiona 
1,  2 and  3 more  highly  magnified. 


97.  What  is  the  number  of  bones  in  the  human  body  ? Give  the  different  groups. 


38 


HITCHCOCK’S  ANATOMY 


Fig.  3G. 


Fig.  37. 


A knee  joint  showing  points  of  ossification, 
1,  2 and  3. 


Head 8 

Ear 6 

Face 14 

Teeth 32 

Yertebrse,  Sacrum  and  Coccyx. ...  26 

Os  Hyoides,  Sternum  and  Ribs 26 

Upper  Extremities 64 

Lower  Extremities 62 

Sesamoid  Bones 8 


246. 


98.  Vertebra;,  Groups  of  Verte- 
bra, Cervical  Vertebra;. — The  Ver- 
tebrae or  Spinal  Column  claim  the 
first  attention,  since  they  are  the 


Description  of  Fig.  37.  view  of  tlic  Si)inal 

Column.  1,  Alla.s,  2,  Axis  (second  Vertebra.)  3,  Last 
Cervical  Vertebra.  4,  Last  Dorsal  V\*rtcbra.  b,  Last 
Lumbar.  G and  7 Sacrum.  8,  Coccyx.  9,  a Spinous 
1‘rocess,  10,  Intervertebral  Foramina. 


AND  niYSIOLOGY 


SD 


Prontal  Bone.  PlGr.  38.  Parietal  Bone. 


Crbit.  — — 


Lower  Jaw.  — 

Cervical  Vertebras. 
Shoulder  Blade. 


Humerus.  * 


I^umbar  Vertebrae. 


Carpus. 

Metacarpus. 


Tibia. 

Fibula. 


Temporal  Bone. 

- Clavicle, 


Ilium. 


Patella. 


, Tarsus. 

Metatarsus. 
, Phalanges. 


40 


HITCHCOCK’S  A N A T O 31  Y 


first  developed  bones,  and  the  center  around  which  the  others 
are  formed.  They  may  be  separated  into  the  true  and  false  : 
or  those  which  are  separable  from,  and  movable  upon  each 
other,  and  those  which  are  firmly  joined  together.  Of  the 
true  vertebrae  there  are  three  sections,  named  in  accordance 
with  their  location  on  the  body  : Cervical,  Dorsal,  and  Lum- 
bar. The  Cervical,  or  those  of  the  neck,  are  seven  in  number, 
the  first  and  second  of  which  are  the  most  remarkable.  The 
first  is  named  Atlas,  from  the  mythological  story  that  a giant 
of  this  name  supported  the  earth  on  his  shoulders,  and  it  is 


Tig.  39. 


Fig.  40. 


The  Atlas.  1,  Anterior  Tubercle.  2,  Articular 
Face.  8,  Posterior  surface  of  Spinal  Canal.  4,  In- 
tervertebral Notch.  5,  Transverse  process.  6,  Fo- 
ramen for  Artery.  7,  Superior  oblique  process. 
8,  Tubercle  for  transverse  Ligament. 


sus  (lentatus.  3,  Articulating  sur- 
face. 4,  Foramen  for  vertebral 
Artery.  5,  Spinous  process.  G aiul 
7,  Oblique  processes. 


upon  this  one  that  the  head  is  moved  in  a direction  backwards 
and  forwards.  The  second,  called  Axis,  is  characterized  by 
a projection  or  pivot,  which  admits  motion  of  the  head  in 
a horizontal  direction,  but  in  no  other.  It  is  the  dislocation 
of  this  process,  and  the  consequent  pressure  upon  the  spinal 
cord  that  causes  death  in  criminals  executed  by  hanging. 

99.  Dorsal  Vertebra. — The  Dorsal  Vertebrae,  or  those  of 
the  back,  are  twelve  in  number,  and  give  attachments  to  all 
the  ribs.  The  central  portion  or  body  of  each  increases  from 
above  downwards,  that  they  may  more  firmly  support  the 
superincumbent  Avcight  of  the  body. 

98.  Why  arc  the  Vcrtcbric  first  described  ? What  two  groups  may  tliey  be  divided 
into?  W'hat  other  three  sections  of  Vertebrse?  What  is  the  name  of  the  first  and 
second  Vertebra?  97.  How  many  Dorsal  vertebra),  and  what  boiios  are  attached  to 
them  ? 


AND  PHYSIOLOGY. 


41 


Fig.  41. 


Fia  42. 


5 


A Dorsal  Vertebra.  1,  The  Body.  2 and 
7,  Faces  for  head  and  tubercle  of  Rib.  3, 
Upper  face  of  the  body.  4 and  5,  Interver- 
tebral Notch.  6,  Spinous  process.  8 and 
9,  Oblique  processes. 


The  Sacrum.  1 and  2,  Articular  sur- 
faces. 8,  Promontory  of  the  Sacrum.  4 
and  10,  Lines  of  former  division  of  Sa- 
crum. 5 and  6,  Foramina.  7,  Sacro  Iscliia- 
tic  Notch.  8,  Abe  of  the  Sacj’iim.  9,  Ob- 
lique processes. 


100.  lumbar  Vertebrae. — The  vertebrae  of  the  Loins,  or 
the  Lumbar,  are  five  in  number,  and  are  the  largest  members 
of  the  spinal  column,  since  they  are  the  only  bones  in  this 
part  of  the  body.  They  are  more  massive  and  solid  in  all 
their  parts  than  the  rest  of  this  column,  that  they  may  be 
equal  to  the  strength  required  of  them. 

101.  Sacrum, — The  Sacrum  is  a single  bone,  although 

its  typical  form  is  that  of  five  vertebrae,  which  are  actually 
found  in  some  animals.  Its  appearance  is  that  of  five  verte- 
brae, which  are  partially  anchylosed  or  grown  together.  The 
form  of  the  bone  is  somewhat  like  a wedge,  with  the  base 
directed  upwards,  and  the  point  curving  inwards  and  for- 
wards. Fig.  43. 


102.  Coccyx, — The  Coccyx  is  the  lower 
extremity  of  the  Spinal  Column,  formed 
of  four  anchylosed  and  imperfect  verte- 
brae ; and  it  is  an  extension  of  these  bones 
in  the  monkey  which  makes  the  tail. 


The  Coccyx.  1,  First  bone. 
2,  3,  Processes  to  join  the 


Sacrum.  4 and  5,  Notches  to  form  Foramen.  6,  Last  bone. 


100.  How  many  Lumbar  Vertebrae?  Why  are  they  the  largest  in  size  ? 101.  Describe  the 
Sacrum.  How  many  rudimentary  vertebrae  does  it  consist  of?  102.  Describe  the  Coccyx. 


42 


11  I T C II  0 O C K ’ S ANATOMY 


103.  General  Remarks  on  the  Spinal  Column. — The 
Spinal  Column  viewed  as  a whole  may  be  considered  as 
made  up  of  four  cones,  owing  to  the  different  sizes  of  the  ver- 
tebrae. The  apex  of  the  upper  one  commences  with  the  Atlas 
and  extends  as  far  as  the  first  dorsal  vertebra.  Here  the 
second  one  commences  in  an  inverted  position,  extending  over 
the  upper  three  dorsal  vertebrae.  The  third  reaches  with  its 
base  as  far  as  the  top  of  the  Sacrum,  where  the  inverted 
fourth  one  terminates  with  the  Coccyx.  Viewed  from  the 
front  the  spinal  column  should  be  in  a straight  line  when  in  a 
healthy  condition ; but  a lateral  view  shows  two  curves,  one 
at  the  lower  part  of  the  neck,  and  the  other  at  the  lumbar 
vertebrae,  the  design  of  this  curvature  being  to  place  the 
head  and  its  delicate  contents  upon  an  elastic  and  flexible 
support,  and  the  design  of  the  straight  position  in  the  other 
direction,  being  to  give  equal  tension  to  the  muscles  on  both 
sides. 

104.  Intervertebral  Cartilage. — Between  all  the  vertebrae 
is  placed  a thick  cushion  of  cartilage.  This  by  yielding  not 
only  allows  a free  and  ready  motion  to  the  column  as  a whole, 
but  is  an  additional  protection  to  the  brain,  by  diminishing 
the  severity  of  any  vibration  communicated  from  below. 

105.  Bones  of  the  Head. — The  Skull  may  be  considered 
as  the  superior  expansion  of  the  spinal  column,  Avhen  it — the 
spinal  column — is  taken  as  the  center  of  development  of  the 
whole  body,  which  contains  in  the  cranium  the  brain,  and  in 
the  face  most  of  the  organs  of  sense. 

106.  In  the  Cranium  or  true  skull  are  eight  bones: 

1 Frontal,  2 Temporal,  2 Parietal, 

1 Occipital,  1 Sphenoid,  1 Ethmoid. 


103.  Of  how  many  cones  may  the  Spinal  Column  bo  considered  as  composed?  From 
what  direction  docs  the  Spinal  Column  appear  in  a straight  line?  Wliat  curvatures  does 
a lateral  view  show  ? 104.  What  substance  do  we  find  between  the  vertebrae?  Give 

Its  use.  105.  What  may  tho  Skull  bo  consldorod  as?  What  organs  does  it  contain? 
lOG.  Give  tho  bones  of  tho  Skull. 


AND  PHYSIOLOGY. 


43 


107.  Frontal, 
T^iriporal,  Parie- 
tn(,  Occipital, 
Spdcnoid,  and  Eth- 
moid Bones. — The 
Frontal  Bone  is  sit- 
uated in  the  upper 
and  front  part  of 
the  head,  occupy- 
ing that  portion  of 
the  skull  called  the 
forehead.  It  is 
mainly  k flat  bone, 
but  the  portion 
lying  above  the  eye 
is  hollow,  in  order 
that  protection  may 
be  afforded  to  this 
delicate  organ,  as 
Avell  as  to  give  sufficient 
prominence  to  the  up- 
per part  of  the  face. 
The  two  Temporal  Bones 
cover  the  front  part  of 
each  side  of  the  skull 
in  that  position  com- 
monly known  as  the 
temples,  and  each  bone 
is  a little  larger  than 
the  space  which  is  pro- 
tected by  the  external 
ear.  In  the  inner  por- 
tions, called  the  petrous, 
are  located  the  organs 


Fia.  44. 


1,  Frontal.  2,  Parietal.  3,  Occipital.  4,  Temporal. 
5,  Nasal.  6,  Malar.  7,  Upper  Jaw.  8,  Lachrymal. 
9,  Mandible. 


Fig.  45. 


Frontal  Bone.  1,  Frontal  Protuberance  of  right 
Bide.  2,  Superciliary  ridge.  8,  Superorbitary 
ridge.  4 and  5,  Angular  processes. 


107.  What  kind  of  a bone  is  the  Frontal  ? Why  is  a portion  of  it  hollow  ? W here  are 
the  Temporal  Bones  located? 


44 


HITCHCOCK’S  anatomy 


of  hearing.  Directly 
behind  the  external  car 
is  felt  a hard  projection 
which  is  the  mastoid 
process  of  this  bone, 
and  serves  for  the 
attachment  of  many 
muscles,  which  move 
the  head.  And  directly 
in  front  of  the  ear  is 
another  prominent  pro- 
cess, called  the  zygo- 
matic, which  articulates 
with  the  malar  bone, 
and  to  which  is  at- 
tached one  of  the  ele- 
vator muscles  of  the 
^jaw.  The  two  Parie- 
tal Bones  are  eminently 
flat  bones  of  a square 
shape,  forming  the  es- 
sential parts  of  the  pro- 
jections on  the  back 
sides  of  the  head,  and 
uniting  with  each  other 
on  the  median  line,  up- 
on the  top  of  the  skull. 
They  join  with  the 
frontal  bone  in  front,  the 
temporal  bones  below, 
and  the  occipital  bone 
behind.  The  Occipital 
Bone  has  an  imperfectly  circular  outline,  and  at  its  lower 


matic  portion.  5,  Articulating  surface  for  lower 
jaw.  6,  Temporal  ridge.  7,  Glenoid  fissure.  8, 
Mastoid  foramen.  9,  Canal  for  ear.  10,  Groove 
for  digastric  muscle.  11,  Styloid  process.  12,  Va- 
ginal process.  18,  Glenoid  Foramen.  14,  Groove 
for  Eustachian  tube. 


Fig.  47. 


Left  Parietal  Bone.  1,  2,  3,  4,  Superior,  Infe- 
rior, Anterior,  and  Posterior  surfaces.  5,  Ridge 
for  Temporal  Fascia.  6,  Parietal  Foramen.  7 and 
8,  Inferior  angles. 


What  is  the  mastoid  process?  Where  is  the  zygomatic  process ? Give  the  form  of 
tlie  Parictals.  What  is  the  outline  of  the  Occipital  Bone  ? What  is  the  large  orifice  in 
its  lower  part  h»r?  Give  the  position  and  general  outline  of  the  Sphenoid  Bone.  With 
what  bones  does  this  articulate? 


AND  PHYSIOLOGY 


45 


edge  a large  orifice  for  the 
passage  of  the  spinal  mar- 
row, just  as  it  enters  the 
vertebrae.  It  is  in  the 
most  posterior  part  of  the 
skull,  joining  with  the 
sphenoid  in  front,  and  rest- 
ing upon  the  Atlas  verte- 
bra. The  Sphenoid  Bone 
is  directly  underneath  the 
skull,  extending  from  side 
to  side,  forming  a very 
small  portion  of  the  out- 
side of  the  skull  at  the 
point  \vhere  the  frontal 
and  temporal  bones  come 
the  nearest  to  each  other. 
From  its  name  we  learn 
that  it  is  somewhat  wedge- 


Fig.  48. 


External  surface  of  Occipital  Bone.  1 and  4, 
Semicircular  Eidges.  2,  Occipital  Protube- 
rance. 3,  Attachment  of  ligamentum  nuclaj. 
5,  Foramen  for  Medulla  oblongata.  6,  Condo  le 
of  right  side.  7 and  8,  Condyloid  Foramina. 
9,  Jugular  Eminence.  10,  Jugular  Foramen. 
11,  Basilar  process.  12,  Points  of  attachment 
for  odontoid  ligaments.  13,  Edge  for  attach- 
ment with  Parietal  bone.  14,  Point  of  attach- 
ment for  Temporal  bone. 


Fig.  49. 


The  Anterior  and  Inferior  Surface  of  the  Sphenoid  Bone.  1, 1,  Apophyses  of  Ingras- 
sias.  2,  2,  The  great  Wings.  3,  Ethmoidal  Spine.  4,  Azygos  Process.  5,  Sphenoidal 
Cells,  after  the  removal  of  the  Pyramids  of  Wistar.  G,  Posterior  Clinoid  Processes. 
7,  Sphenoidal  Fissure.  8,  Foramen  Rotundurn.  9,  Depression  for  the  Middle  Lobes  of 
the  Cerebrum.  10,  Surface  for  the  Temporal  Muscle.  11,  Styloid  Process.  12,  Exter- 
nal Pterygoid  Process.  13,  Internal  Pterygoid  Process.  14,  Pterygoid  Foramen.  15,  Ar- 
ticular Face  for  the  Os  Frontis.  16,  Points  to  the  Sella  Turcica. 


46 


HITCHCOCK’S  ANATOMY 


shaped  in  its  general  outline,  although  it  is  covered  and 
filled  with  cavities  and  processes  t for  the  protection  and 
proper  direction  of  many  of  the  delicate  organs  which  pass 
through  it  to  their  destination.  This  bone  articulates  with 
all  those  in  the  cranium,  and  five  of  those  in  the  face,  and 
serves  as  a point  of  attachment  for  twelve  pairs  of  muscles, 
alnd  is  one  of  the  most  complicated  bones  belonging  to  the 
human  skeleton. 

The  last  bone  of  the  skull  is  situated  at  the  base  of 


Cribriform  Plate.  5,  Superior  Meatus.  A View  of  the  Outside  of  the  Vault  of 

6,  Superior  Turbinated  Bone.  7,  Middle  the  Cranium,  showing  the  Sutures.  1,  The 

Turbinated  Bone.  8,  Os  Pb.nutn.  9,  Sur-  Coronal  Suture.  2,  The  Sagittal  Suture, 

face  for  the  Olfactory  Nerve.  3,  The  Lambdoidal  Suture. 


the  front  portion  of  the  cranium,  between  the  sockets  of 
the  eyes,  and  behind  the  root  of  the  nose.  It  is  called  the 
Ethmoid  Bone.  Its  outline  is  that  of  a cube,  consisting  of  a 
perpendicular  plate,  and  two  lateral  portions.  From  the 
fact  that  it  is  extremely  fragile,  owing  to  the  great  number 
of  perforations  which  it  contains,  it  derives  its  name  from  the 
Greek  word  signifying  a sieve.  It  is  so  deeply  seated  that  it 
receives  the  attachments  of  no  muscles. 

108.  S 111 n res. — The  bones  of  the  skull  are  united  by 


Give  tho  shape  and  position  of  the  Ethmoid  bone.  Why  called  Ethmoid? 


AND  PHYSIOLOGY. 


47 


ragged  edges  called  Sutures.  These  are  small  and  rough 
projections  of  bone  which  are  largest  at  their  extremities. 
They  are  made  to  fit  into  the  edges  of  the  opposite  bone  with 
great  firmness,  thus  joining  the  bones  together,  by  essentially 
the  same  process  which  in  cabinet  work  is  known  as  dovetail- 
ing. The  name  Suture  is  applied,  since  when  these  edges 
are  perfectly  joined  by  this  \articulation,  they  resemble  the 
seam  made  by  sewing  together  two  pieces  of  cloth  by  the 
‘^over  and  over’’  stitch.  Situated  directly  within  these  sut- 


ures are  frequently  found 
small  bones,  uncertain  as  to 
number,  sometimes  two  inches 
in  diameter,  called  Ossa  Tri- 
quetra.  No  special  use  for 
them  has  been  discovered  as 
yet. 

109.  The  Lower  Surface 
of  the  Skull.— The  whole  of 
the  lower  surface  of  the  skull 
is  extremely  uneven  for  the 
attachment  of  a great  number 
of  muscles,  and  the  protection 
of  delicate  nerves  and  blood- 
vessels which  pass  to  and 
from  the  brain  and  face. 

110.  Bones  in  the  Face. — 
The  Face  is  that  portion  of 
the  head  situated  below  a line 
drawn  from  the  orbit  of  the 
eye  to  the  passage  of  the  in- 
ternal ear.  Its  framework  con- 
tains fourteen  bones.  2 Nasal ; 


Fi&.  52. 


A Front  View  of  che  Skull,  showing  the 
Bones  composing  the  Face.  1,  Os  Frontis. 
2,  Nasal  Tuberosity.  3,  Supra-Orbital  Ridge. 
4,  Optic  Foramen.  5,  Sphenoidal  Fissure. 
6,  Spheno-Maxillary  Fissure.  7,  Lachrymal 
Fossa,  and  commencement  of  the  Nasal  Duct. 
8,  Opening  of  the  Anterior  Nares,  and  the 
Vomer.  9,  Infra-Orbital  Foramen.  10,  Ma- 
lar Bone.  11,  Symphysis  of  the  Lower  Jaw. 
12,  Anterior  Mental  Foramen.  13,  Ramr.s  of 
the  lower  Jawbone.  14,  Parietal  Bone,  1,'\ 
Coronal  Suture.  16,  Temporal  Bone.  IT, 
Squamous  Suture.  18,  Great  Wing  of  the 
Sphenoid.  19,  Commencement  of  the  Tem- 
poral Ridge.  20,  Zygomatic  Process.  21,  Mas- 
toid Process. 


How -do  the  bones  of  the  skull  join  with  each  other  ? What  process  in  cabinet  making 
does  it  correspond  to  ? What  are  often  found  in  these  sutures?  109.  AVhat  is  the  sur- 
face of  the  lower  part  of  the  skull  ? 110.  Give  the  boundaries  of  the  face. 

3 


48 


II  I T C ir  c O C K ’ S A N ATOMY 


2 Malar ; 2 Lachrymal ; 2 Superior  Maxillary ; 2 Palate : 
2 Turbinated ; 1 Inferior  Maxillary ; 1 Vomer. 

111.  Nasal  Bones . — The  Nasal  Bones  are  oblong,  foursided 
bones,  about  an  inch  in  length,  which  together  form  the 
bridge  or  base  of  the  nose. 

Fia.  53.  Fig.  54. 


An  Anterior  and  Posterior  View  of  tlie 
Nasal  Bones.  Right  Hand  Figure.  1,  An- 
terior Inferior  Extremity.  2,  Articulating 
Surfixce  for  its  Fellow.  3,  Surface  for  the 
Nasal  Process  of  the  Superior  Maxillary 
Bone.  4,  Points  to  the  Groove  on  the  In- 
ner Side,  for  the  Nasal  Nerve.  5,  Articu- 
lar Face  for  the  Os  Frontis.  6,  Foramen 
for  the  Nutritious  Artery. — Left  Hand 
Figure.  1,  Posterior  Inferior  Extremity. 
2,  Surface  for  its  Fellow.  8,  Surface  for 
the  Superior  Maxilla.  4,  Groove  for  the 
Internal  Nasal  Nerve.  5,  Surface  for  the 
Os  Frontis.  6,  Lower  portion  of  the 
Groove  for  the  Nasal  Nerve. 


3 


An  Anterior  Yiew  of  the  Malar  Bone 
of  the  Bight  Side.  1,  Anterior  Oroital 
Angle.  2,  Orbital  Face.  3,  Superior  An- 
gle for  articulating  with  the  Os  Frontis. 
4,  External  An,le  for  the  Zygoma  of  the 
Temporal  Bone.  5 and  6,  Inferior  An- 
gle and  Surface  for  the  Superior  Maxilla. 
7,  Nutritious  Foramen. 


112.  Malar  Bones. — The  Malar  Bones  give  the  promi- 
nence and  form  to  the  cheek.  They  are  partially  hollow,  of 
an  irregularly  quadrangular  outline,  and  articulate  with  the 
frontal  above,  the  zygomatic  process  of  the  temporal  behind, 
and  the  superior  maxillary  below.  The  name  is  from  the 
Latin  Ma/a,  a cheek/’  hence  cheek  bones. 

113.  Ijaclirymal  Bones. — The  Lachrymal  Bones  are  the 


IIow  many  hones  in  tlio  Face,  and  what  aro  their  names ? 111.  Describe  the  Nasal 
Bones.  1 12.  WJiat  bones  aro  found  in  the  cheeks  ? 


AND  PHYSIOLOGY. 


49 


smallest  bones  in  the  Face,  being  about  |th  of  an  inch  in 
diameter.  They  are  situated  at  the  inner  angle  of  the  eye, 
and  are  named  from  the  Latin  Lachryma^  a tear/’  since 
the  tears  pass  into  the  nostrils  through  a canal  in  these 

bones.  This  bone  is  also  called  Os  Unguis. 

Fig.  56. 


An  Anterior  View  of  the  Os  Un- 
guis of  the  Left  Side.  1,  Its  An- 
terior Inferior  Angle.  * 2,  Orbitar 
Plate  and  Side  for  the  Os  Pla- 
num. 3,  Fossa  for  the  Lachry- 
mal Sac.  4,  Superior  Extremity. 


A Posterior  and  Half  Lateral  View  of  the  Pal- 
ate Bone,  1,  Palate  Plate  on  its  Nasal  Surface. 
2,  Nasal  Plate.  3,  Pterygoid  Process.  4,  Sur- 
face for  Articulating  with  its  fellow.  5,  Half 
of  the  Crescentic  Edge  and  Spine  for  the  Azygos 
Uvuhe  Muscle.  6,  Bidge  for  the  Inferior  Spongy 
Bone.  7,  Spheno-Palatinc  Foramen.  8,  Orbital 
Plate.  9,  Pterygoid  Apophysis.  10,  Depression  for  the  External  Pterygoid 
Process  of  the  Sphenoid  Bone.  11,  Same  for  the  Internal  Pterygoid  Process, 


114.  Palate  Bones, — The  Palate  Bones  are  the  most  ir- 


regular bones  of  the  face,  and 
resemble  the  capital  letter  L. 
of  the  eye,  the  wall  of  the 
nose,  and  a large  part  of  the 
roof  of  the  mouth  which  is 
known  as  the  hard  palate. 

115.  Turbinal  Bones. — 
The  Turbinal  Bones  (really 
the  Inferior  Turbinated 
Bones,  since  corresponding 
plates  upon  the  ethmoid  bone 
are  called  Superior  Turbinated 


when  viewed  in  one  direction 
They  form  a part  of  the  orbit 
Fig.  51. 


4 


An  External  View  of  the  Inferior 
Spongy  Bone  of  the  Right  Side.  1,  An- 
terior Extremity,  for  resting  on  the 
Ridge  of  the  Upper  Maxilla,  2,  Posterior 
for  resting  on  the  Ridge  of  the  Palate 
Bone.  3,  Hooked  portion,  for  resting  on 
the  Lower  Margin  of  the  Antrum  High- 
morianum.  4,  Its  Inferior  Border. 


113.  What  arc  the  smallest  bones  of  the  face,  and  why  called  Lachrymal  ? 114.  "What 
are  the  most  irregularly-shaped  bones  in  the  face,  and  what  portion  of  the  mouth  is 
made  up  by  the  Palate  Bones?  115.  Give  the  description  of  the  Turbinal  Bones. 


5) 


II  I T C II  C O O K ’ S ANATOMY 


Bones')  are  curved  laminye  or  thin  ])latc3  of  bone,  resembling 
a loose  scroll,  and  are  found  in  each  nostril,  for  the  j)ur|)03e 
of  affording  as  large  a surface  as  possible  for  the  expansion 
of  the  mucous  membrane  of  the  nose,  which  contains  the 
nerves  of  smell.  The  name  Turbinal  or  Turbinated  is  ap- 
l)]ied  because  of  their  scroll-like  appearance. 

116.  Siippi’ior  Jinx  illary  Bone.— The  Superior  Maxilla- 
ries  are  the  largest  bones  of  the  face,  joining  with  each  other 


An  External  View  of  the  Superior  Max-  The  Inferior  Maxillary  Bone.  1,  Tho 
ilia  of  the  Left  Side.  1,  Orbitar  Process.  Body.  2,  The  Ramus.  3,  The  Syniphy- 

2,  Infra-Orbitar  Canal.  3,  Space  for  the  sis.  4,  Alveolar  Process.  6,  Anterior 

Os  Unguis.  4,  Upper  part  of  the  Lachry-  Mental  Foramen.  6,  The  Base.'  7, 

inal  Canal.  5,  Nasal  Process,  and  Sur-  Groove  for  the  Facial  Artery.  8,  Tho 

face  for  Articulating  with  the  Os  Frontis.  Angle.  9,  Extremity  of  the  Ridge  for 

G,  Surface  for  the  Nasal  Bone.  7,  Anterior  the  Mylo-IIyoid  Muscle.  10,  Coronoid 

portion  of  the  Floor  of  the  Nostril.  8,  Sur-  Process.  11,  Condyle.  12,  Neck  of  tho 

face  for  Articulating  Avith  its  Fellow.  9,  Al-  Condyloid  Process.  13,  Posterior  Men- 

A'oolar  Process.  10,  Points  to  the  Depression  tal  Foramen.  14,  Groove  for  the  Infe- 

just  below  the  Infra-Orbitar  Foramen.  11,  rior  Maxillary  Nerve.  15,  Molar  Teeth. 

Surface  for  the  Malar  Bone.  16,  Bicuspidate  Teeth.  17,  13,  Middle 

and  Lateral  Incisors. 

on  the  median  line,  and  thus  form  a portion  of  the  roof  of 
the  mouth.  Each  one  of  them  articulates  with  eight  teeth, 
with  all  the  bones  of  the  face  but  the  lower  jaw,  and  two  of 
the  cranium.  Their  name  is  from  the  Latin,  Maxilla^  a 
jaw/’  and  both  of  them  constitute  the  upper  jaw. 

117.  Miilidiblc. — The  Inferior  Maxillary,  or  lower  jaw,  is 


11G.  How  arc  tlio  Superior  Maxillaricis  situated  ? How  many  teeth  arc  found  in  each 
ortliemV  117.  Describe  tho  Mandible. 


AND  PHYSIOLOGY. 


51 


the  only  movable  bone  of  the  head  or  face.  It  contains  the 
sixteen  lower  teeth,  is  of  an  arched  form,  and  at  each  ex- 
tremity has  a square-shaped  process  for  articulation  with  the 
temporal  bones,  and  the  attachment  of  muscles. 


118.  Vomer. — The 
name  of  the  Vomer  is 
derived  from  the  Latin 
meaning  a “plow- 
share,” on  account  of 
its  approximate  resem- 
blance to  that  object. 
It  completely  separates 
the  nostrils  from  each 
other,  and  like  the  tur- 
binated bones  gives  at- 
tachment to  no  mus- 
cles. 


Fig.  60. 


The  Vomer.  1,  2,  Posterior  and  Superior  Surface 
hollowed  to  receive  the  Azygos  Process  of  tho 
Sphenoid  Bone.  3,  Anterior  Surface  for  the  Car. 
tilaginous  Septum  of  the  Nose. 


119.  Number  of  Teeth. — The  Teeth  of  the  Human  Adult 
when  all  present  in  the  jaws,  number  thirty-two.  And  al- 
though properly  bones,  still  they  differ  in  three  respects : 

1st,  Organic  Composition. 

2nd,  Time  of  Development  and  Replacement. 

3d,  Decay  when  fractured. 

120.  Organic  Composition,  Cementum,  Dentine,  Enamel, 
Microscopic  Structure  of  Enamel,  Development  of  Teeth, 
Nasmyth’s  Membrane.— The  Teeth  are  composed  of  three 
substances : a Cementum  which  forms  a thin  coating  on  the 
fangs  of  the  teeth,  and  which  thickens  in  advanced  life  ; the 
Dentine  which  resembles  bone  in  its  external  characteristics 
and  makes  the  largest  part  of  the  teeth,  containing  the  prin- 
cipal vessels  and  nerves  of  the  teeth ; and  the  Enamel,  the 
hardest  substance  in  the  human  body,  which  is  a covering  to 


IIS.  From  w’h at  does  the  Vomer  derive  its  uamc?  What  two  cavities  does  it  sep- 
arate ? 119,  IIow  many  teeth  in  an  adult?  In  what  respects  do  they  differ  from  the  other 
bones  of  the  body?  120.  Of  what  substances  are  tho  teeth  composed? 


52 


HITCHCOCK’S 


A N A T O INI  Y 


Fig.  61. 


■Vertical  Section  of  Human  Incisor, 
the  point  where  the  Gum  is  attached 
the  Tooth. 


Fig.  63.  Fig.  64. 


A View  of  an  Incisor  and  of  a Molar 
Tooth,  given  by  a Longitudinal  Section, 
and  showing  that  the  Lnaihcl  is  striated 
and  that  the  Strim  are  all  turned  to  tho 
center.  Tho  Internal  Structiiro  Is  also 
sc(m.  1,  Tho  Enamel,  2,  The  Ivory.  8, 
Tho  Cuvitas  Pulpi. 


Fig.  62. 


A Vertical  Section  of  an  Adult  Bicuspid, 
cut  from  without  inwards;  magnified  four 
times.  1,  1,  The  Cementuin  which  sur- 
rounds the  Root  up  to  the  commencement 
of  the  Enamel.  2,  2,  The  Dentine  of 
the  Tooth,  in  which  are  seen  the  greater 
Parallel  Curvatures,  as  well  as  the  position 
a,  of  the  Main  Tubes.  3,  Apex  of  the  Tooth, 
to  where  the  Tubes  are  almost  perpendicular. 
4,  4,  The  Enamel.  5,  The  Cavity  of  tho 
in  which  are  seen,  by  means  of  the  Glass^ 
Openings  of  the  Tubes  of  the  Dental  Bone. 

all  the  tooth  above  the  gums. 
This  is  a pure  -white  sub- 
stance, thickest  upofl  the  top 
of  the  crown,  and  gradually 
growing  thinner  towards  the 
gum,  where  it  disappears  al- 
together. Under  the  micro- 
scope it  is  seen  to  be  made 
up  of  minute  hexagonal  fibers, 
one  end  of  which  rests  upon 
the  Dentine,  and  the  other 
forms  the  free  surface  of  the 
tooth.  These  tubes  or  fibres 
arc  slightly  undulating  and 


AND  PHYSIOLOGY 


53 


from  8 oVoth  to  54V 3d  of  an 
inch  in  diameter.  The  en- 
amel is  also  covered  by  a very 
thin  membrane,  rjbs  ist  of  an 
inch  in  diameter,  called  Nas- 
myth’s membrane.  This  is 
a calcified”  membrane  and 
can  be  seen  only  with  great 
care,  since  it  is  not  acted  up- 
on by  the  strongest  acids  or 
alkalies. 

121.  Development  of  Tectli. 

Temporary  Set.  Permanent 
Set. — The  teeth  in  the  human  subject  are  not  perfectly  formed 
at  birth,  but  exist  in  the  form  of  follicles  or  shut  sacs,  which 
at  the  seventh  or  eighth  month  of  infantile  life,  are  developed 
into  teeth.  The  process  of  dentition  generally  occupies  from 
one  to  three  years,  during  which  time  the  temporary  set,  as 
it  is  termed,  make  their  appearance.  These  number  twenty, 
ten  in  each  jaw,  and  between  the  age  of  seven  and  fourteen 
become  loose,  and  are  easily  removed  to  give  place  to  the  per- 
manent set  which  numbers  thirty-two.  Generally,  however, 
the  last  tooth  in  each  jaw  does  not  make  its  appearance  until 
the  twentieth  year  of  life. 

122.  A more  accurate  statement  of  dentition  of  the  tempo- 
rary teeth  shows  that  they  a'lrpear  at  the  following  ages : 


The  Incisors,  from  the 

Ith  to  the 

10th 

rnonth. 

The  Anterior  Molars, 

12th  “ 

13th 

11 

The  Canine  Teeth, 

14th  ‘‘ 

20  th 

n 

Posterior  Molars, 

18th  “ 

36th , 

u 

Fig.  65. 


A portion  of  the  Surface  of  the  Enamel 
on  which  the  Hexagonal  Terminations  of 
the  Fibres  are  shown  ; highly  magnified. 
1 2,  3,  Are  more  strongly  marked  dark, 
crooked  Crevices,  running  between  the 
rows  of  the  Hexagonal  Fibres. 


123.  The  permanent  teeth  appear  as  follows : 


Describe  each  of  the  teeth.  What  membrane  completely  covers  the  outside  of  the 
tooth?  121.  Illustrate  the  development  of  the  teeth.  122.  Give  the  time  of  appearance 
of  the  temporary  teeth.  123.  When  do  the  permanent  teeth  appear  ? 


54 


TI  I T C TI  C OCR’s  A N A T O M Y 


I 


Incisors,  from  tlio  8tl>  to  tho  9th  year. 

Bicuspids,  10th  “ 11th  “ 

Canines,  12tli  “ 12Jth  “ 

Second  Molars,  12JtIi  “ 14th  “ 

Third  Molars,  17th  “ 19th  “ 

124.  Names  of  Teeth. — A third  set  of  teeth  has  been 
known  to  make  its  appearance ; also  a tooth  extracted  and 
at  once  replaced  may  become  firm  again  at  the  end  of  some 
months. 

The  names  and  number  of  the  permanent  teeth  in  each 
jaw,  beginning  at  the  posterior  part  of  the  mouth,  are  : 

2 Wisdom,  4 Molars,  4 Bicuspids,  2 Canine,  4 Incisors. 


Fig.  6G. 


a,  1)^  Incisoi«.  c,  Canine,  d,  Bicuspids.  /,  Molars.  A Wisdom  teeth. 


125.  Fracture  of  Teeth. — All  the  bones  of  the  body,  ex- 
cept the  teeth,  when  broken  will  become  united  again  ; but  if 
the  teeth  lose  a portion  of  their  enamel,  or  even  if  it  be 
cracked,  the  tooth  so  injured  at  once  begins  to  dec^ay,  and 
will  be  entirely  consumed,  unless  the  disease  be  checked  by 
artificial  means. 


124.  What  i.s  said  about  a third  set?  Give  tho  names  of  tho  permanent  teeth. 
125.  What  it  tho  teeth  aro  lirokcn  or  cracked  ? 


AND 


PHYSIOLOGY. 


55 


126.  Hyoid  Bone.  — The 
Hyoid  Bone  is  the  bone  which 
forms  the  base  of  the  tongue, 
and  the  upper  extremity  of 
the  trachea.  It  has  the 
shape  of  the  Greek  letter  U 
(or  Upsilon)  and  articulates 
with  no  other  bones,  but  is 
completely  enveloped  by  the 
soft  parts.  It  has  a consi- 
derable range  of  motion  in  a 
vertical  direction,  and  hence  gives  attachment  to  no  less 
than  eleven  pairs  of  muscles. 

127.  Sternum. — The  Breast  Bone  is  flat,  about  eight 
inches  in  length,  one  and  a half  in  width,  and  is  located  on 
the  median  line  of  the  body  upon  the  front  portion  of  the  tho- 
rax or  chest,  articulating  with  the  seven  upper  ribs  on  both 
sides,  and  also  with  the  clavicle. 

128.  Ribs. — There  are  twenty-four  ribs  in  the  human 

Fig.  69. 


3 

A View  of  the  Upper  Side  of  the  First 
Kib  of  the  Right  Side,  half  the  size  of  na- 
ture. 1,  The  Head.  2,  The  Tubercle.  8, 
Anterior  Surface.  4,  Groove  for  the  Sub- 
clavian Artery.  5,  Groove  for  the  Sub- 
clavian Vein.  6,  Anterior  Extremity  for 
A Front  View  of  the  Sternum.  1,  First  the  Cartilage.  7,  Tubercle  for  the  Scalenus 
Piece.  2,  Second  Piece.  3,  Ensiform  Car-  Anticus  Muscle, 
tilage,  or  Third  Piece.  4,  Articular  Face 

for  the  Clavicle.  5,  Articular  Face  for  the  First  Rib.  6,  Articular  Face  for  the  Second 
Rib.  7,  8,  9,  10,  Articular  Faces  for  the  Last  Five  True  Ribs. 

126.  Where  is  the  Hyoid  Bone?  What  Greek  letter  does  it  resemble  ? 127.  Describe 
the  Sternum.  With  what  bones  does  it  articulate  ? 128.  Number  of  Ribs  in  man? 

3* 


Fig.  67. 


An  Anterior  View  of  the  Os  Hyoides, 

1,  The  Anterior  Convex  Side  or  the  Body. 

2,  The  Cornu  Majus  of  the  Left  Side.  3, 
The  Cornu  Minus  of  the  same  Side.  The 
Cornua  were  ossified  to  the  Body  of  the 
Bone,  in  this  specimen. 


HITCHCOCK’S  ANATOMY 


5G 


Tia.  ^0. 


General  Character  of  the  other  Ribs,  seen  on  their  Upper  and  Under  Surface.  The 
left  hand  figure  is  the  Upper  Face  of  the  Rib.  1,  Head  of  the  Rib.  2,  Its  Tubercle. 
3,  Anterior  Extremity  for  the  attachment  of  the  Costal  Cartilage.  4,  Groove  for  the  Ar- 
tery and  Nerve.  5,  Angle  of  the  Rib.  The  right  hand  figure  is  the  Under  Surface  of 
the  Rib.  1,  The  Head.  2,  Its  Tubercle.  8,  Anterior  Extremity.  4,  Groove  for  Inter- 
costal Artery  and  Nerve.  5,  Angle  of  the  Rib. 


body,  which  are  divided  into  two  classes,  the  true  and  the 
false,  or  those  which  are  closely  united  with  the  sternum, 
and  those  which  are  remotely  attached  to  it  by  long  cartilages. 
They  are  attached  at  their  posterior  extremities  to  the  verte- 
brae, and  run  downwards  and  forwards,  so  that  when  elevated, 

Fig.  11. 

Vertebral  Column.  Ribs. 


AND  PHYSIOLOGY. 


57 


they  enlarge  the  cavity  of  the  chest.  The  true  ribs  are  the 
seven  uppermost  ones,  and  the  false  the  five  lower  ones,  and 
are  so  arranged  that  they  form  a cone  with  the  apex  at  the 
neck.  The  two  lowest  ribs  are  sometimes  called  ^^floatino- 
because  they  are  only  attached  to  the  vertebrae. 

129.  Clavicle. — 

The  Collar  Bone  is  the  2. 

commencement  o f 

the  upper  extremity. 

It  is  one  of  the  class 
of  long  bones  ex- 
tending from  the  Anterior  View  of  the  Claviele  of  the  Right 

highest  point  of  the  side,  l,  The  Anterior  Faec  of  the  Body  of  the  Bone. 

, 2,  Origin  of  the  Clavicular  portion  of  the  Stcrno- 

SCapula  to  the  upper  Cleido-Mastoid  Muscle.  8,  The  Sternal  Extremity  of 
Dart  of  the  sternum  Bone.  4,  The  Acromial  Extremity  of  the  Bone. 

^ 5,  Articular  Face  for  the  Acromion  Process  of  the  Scapu- 

and  bears  a partial  la.  6,  Point  of  Attachment  of  the  Conoid  Ligament, 
resemblance  to  the  Point  of  Attachment  of  fhe  Rhomboid  Ligament. 

Italic  letter  F.  The  name  is  from  the  Latin  Clavis^  *^a 
key/’  since  it  remotely  resembles  an  antique  key. 

130.  Scapula. — A large,  flat,  and  triangular  bone  upon 
the  upper  part  of  the  back,  and  forming  the  shoulder,  is 
called  the  Scapula,  or  Shoulder  Blade.  It  has  a high  and 
narrow  ridge  running  through  its  longest  diameter,  which  is 
the  bone  so  distinctly  felt  upon  the  shoulder  and  upper  part 
of  the  back.  Its  only  articulations  are  with  the  clavicle  and 
humerus,  the  posterior  part  being  kept  in  its  place  by  mus- 
cles and  ligaments.  (Fig.  73,  p.  58). 

131.  Humerus. — The  Humerus  is  the  bone  of  the  upper 
arm  or  shoulder.  (Fig.  74,  p.  58.)  It  is  a long  bone  with 
a cylindrical  shaft,  and  has  a rounded  head  for  its  upper  ex- 
tremity. The  lower  extremity  is  flattened  from  before  back- 

What  two  classes  are  they  divided  into?  What  do  they  all  unite  with  behind? 
129.  What  two  bones  does  the  Clavicle  unite  with  ? 180.  What  is  the  general  outline  of 
the  Scapula?  Where  is  it  located?  What  are  its  only  articulations ? 131.  What  is  the 

bone  of  the  upper  arm  ? 


58 


II I TO  IT  COCK’S  ANATOMY 


Fio.  13. 


Ym.  1i. 


A Posterior  View  ot  the  Scapula  of  the 
Left  Side.  1,  Fossa  Supra-Spinata.  2,  Fos- 
sa Infra-Spinata.  8,  Superior  Margin.  4, 
Coracoid  Notch.  5,  Inferior  Margin.  6, 
Glenoid  Cavity.  7,  Inferior  Angle.  8,  The 
Neck  and  Point  of  Origin  of  the  Long  Head 
of  the  Triceps  Muscle.  9,  Posterior,  or 
Vertebral  Margin.  10,  The  Spine.  11, 
Smooth  Facet  for  the  Trapezius  Muscle. 
12,  Acromion  Process.  13,  Nutritious  Fo- 
ramen. 14,  Coracoid  Process.  15,  Part  of 
the  Origin  of  the  Deltoid  Muscle. 


An  Anterior  View  of  the  Humerus  of  the 
Eight  Side.  1,  The  Shaft,  or  Diaphysis  of 
the  Bone.  2,  The  Head.  3,  Anatomical 
Neck.  4,  Greater  Tuberosity.  5,  Lesser 
Tubero.sity.  6,  The  Bicipital  Groove.  7, 
External  Bicipital  Eidge  for  the  insertion 
of  the  Pectoralis  Major.  8,  Internal  Bici- 
pital Eidge.  9,  Point  of  insertion  of  the  Deltoid  Muscle.  10,  Nutritious  Foramen. 
11,  Articular  Face  for  the  Head  of  the  Eadius.  12,  Articular  Face  for  the  Ulna. 
13,  External  Condyle.  14,  Internal  Condyle.  15,  16,  The  Condyloid  Kidges.  17, 
Lesser  Sigmoid  Cavity. 


wards,  and  so  formed  into  grooves  and  elevations  that  it  ar- 
ticulates with  the  ulna  in  essentially  the  same  manner  as  the 
two  portions  of  a door  hinge. 

132.  Fore-arm.  Tlie  Ulna. — There  are  two  bones  in  the 
forearm,  one  of  which  only  is  articulated  with  the  humerus, 
and  the  other  to  the  bones  of  the  wrist  alone,  in  order  to  al- 
low the  rotation  of  the  hand  upon  the  bones  of  the  forearm, 


Wliat  i.i  the  shape  of  the  lower,  or  ulnar  articulation?  182.  How  many  bones  in  the 
foreanri  ? Why  are  there  two  instead  of  one  ? 


AND  PHYSIOLOGY. 


59 


as  if  they  constituted  a pivot ; 
an  instance  of  which  is  seen  in 
the  turning  of  a screw,  or  in 
the  unlocking  of  a door.  Of 
these  two  boaes  the  Ulna  arti- 
culates with  the  humerus,  form- 
ing only  a ligamentous  union 
with  the  bones  of  the  wrist. 
It  is  prismoid  in  form,  and  is 
of  a hooked  shape  at  its  up- 
per extremity,  so  that  it 
makes  the  union  between  it- 
self and  the  humerus  a very 
secure  one.  The  word  ulna 
is  a Latin  term  signifying  an 
ell,  because  the  forearm  in 
early  times  was  used  for  that 
measure. 


133.  The  Radius. — The 
Radius  is  the  mate  of  the 
ulna.  Its  upper  extremity  is 
the  smallest,  and  the  lower 
the  largest,  since  its  only  true 
articulation  is  at  the  wrist. 

A firm  membrane,  however, 
unites  this  bone  to  its  fellow  nearly  its  whole  length.  It  prob- 
ably derives  its  name  from  the  fact  that  it  measures  the  ra- 
dius of  a circle  which  may  be  described  by  the  hand  about 
the  elbow  as  a center. 


Bones  of  the  Forearm.  1,  The  Ulna. 
2 and  3,  The  Sigmoid  Notches.  4,  The 
Olecranon  Process.  5,  Coronoid  Process. 
6,  Nutritious  Foramen.  7.  Ridge  for  at- 
tachment of  Interosseous  Membrane.  8, 
Capitulum  Ulnje.  9,  Styloid  Process.  10, 
Shaft  of  the  Radius.  11,  12  and  13,  Head, 
Neck,  and  Tuberosity  of  Radius.  14,  Ob- 
lique Line  for  muscular  attachments.  15, 
Styloid  Process. 


134.  The  Carpus. — The  bones  of  the  Carpus  or  Wrist  are 
eight  in  number,  are  small  and . irregular,  and  have  the  gen- 
eral disposition  of  two  rows.  The  first  row,  commencing  with 
the  one  nearest  the  thumb,  contains  the  Scaphoid,  Semilunar, 


In  what  operations  do  we  need  the  two  bones  of  the  forearm  ? Give  the  derivation  of 
ulna.  133.  What  is  the  mate  of  the  ulna?  Where  does  this  articulate?  What  is  the 
derivation  of  its  name  ? 184.  How  many  bones  in  the  wrist?  Give  their  names. 


CO 


II  T T G II  G O G IC  ’ S A N-  A T O ]M  Y 


Fig.  7G. 


A Posterior  Yiew  of  the  Articulations 
of  the  Bones  of  the  Carpus  in  the  Bight 
Hand,  1,  The  Ulna.  2,  The  Badius.  3, 
Inter-Articular  Fibro-Cartilage.  4,  Meta- 
carpal Bone  of  the  Thumb.  5,  Metacarpal 
Bone  of  the  First  Finger.  C,  Metacarpal 
Bone  of  the  Second  Finger.  7,  Metacar- 
pal Bone  of  the  Third  Finger.  8,  Meta- 
carpal Bone  of  the  Fourth  Finger.  S,  The 
Scaphoides.  L,  The  Lunare.  C,  The  Cu- 
neiforme.  P,  The  Pisiforme.  T,  T,  Tra- 
pezium and  Trapezoides.  M,  The  Mag- 
num. U,  The  Unciforme. 


Fig.  V7. 


An  Anterior  View  of  the  Left  Hand. 
1,  The  Scaphoides.  2,  The  Lunare.  3, 
The  Cuneiforine.  4,  The  Pisiforme.  5, 
The  Trapezium.  6,  Groove  for  the  Flexor 
Carpi  Badialis  Tendon.  7,  The  Trape- 
zoides. 8,  The  Magnum.  9,  The  Unci- 
forme. 10,  10,  The  Five  Meta-Carpal 
Bones.  11,  11,  First  Bow  of  Phalanges. 
12,  12,  Second  Bow  of  Phalanges.  13,  13, 
Third  Bow  of  Phalanges.  14.  First  Pha- 
lanx of  the  Thumb.  15,  Last  Phalanx  of 
the  Thumb. 


Cuneiform,  and  Pisiform.  The  second  in  the  same  order,  the 
Trapezium,  Trapezoid,  Magnum,  and  Unciform. 

135.  The  Metacarpus. — The  Metacarpus  contains  five 
bones.  Each  of  these  articulate  with  the  carpus  above,  and 
the  phalanges  below,  being  found  in  the  space  known  as  the 
palm  or  body  of  the  hand. 

186.  The  Phalanges. — The  Phalanges  are  tlie  bones  of 
the  thumb  and  fingers,  two  in  the  former,  and  three  in  the 
latter,  making  fourteen  in  each  hand. 


135.  Describe  tlio  Metacarpal  Bones.  What  part  of  the  hand  do  they  occupy? 
130,  How  many  Plialangos  in  the  thumb,  and  how  many  in  each  finger?  What  is  the 
whole  number  of  them? 


AND  P II  S I O L O G Y . 


Cl 


137.  Bones  of  the  Pelvis. — The  bones  of  the  Pelvis  are 
the  two  Innominata  or  nameless  bones,  and  the  Sacrum  and 
Coccyx,  which  have  already  been  described.  (Fig.  78.) 


Fig.  78. 


138.  The  Iniiominatuin,  Ilium,  Ischium,  Puhes, — Each 
Innominatum  presents  the  largest  surface  of  any  bone  in  the 
body.  They  are  irregularly  flat  bones  and  situated  just 
beneath  the  abdomen,  to  the  organs  of  which  they  give  firm 
support  by  their  broadly-expanded  surface.  In  young  skele- 
tons they  are  divided  into  three  portions,  and  hence  they  are 
described  in  the  adult  as  made  up  of  three  parts,  although  no 
line  of  division  can  actually  be  seen.  The  Ilium  constitutes 
the  broadly-expanded  portion  usually  known  as  the  hip  or 
haunch.  The  Ischium,  from  the  Greek  signifying  to  hold’^ 
or  ‘'retain,’’  is  the  heavy  portion  projecting  downwards,  and 
that  point  on  which  the  body  rests,  when  in  a sitting  posture. 

137.  IIow  many  bones  in  the  Pelvis,  and  what  are  their  names?  138.  Describe  the 
Innominatum.  Into  how  many  parts  are  they  divided  in  young  animals?  Describe 
the  Ilium  and  the  Ischium. 


G2 


IT  I T c ir  c O C K ’ S A N A T o :\r  \ 


Fig.  10. 


Outside  of  the  Innominatiim  of  the  Right  Side. 
1,  Dorsum  of  the  Ilium.  2,  Ischium.  3,  Pubis. 
4,  Crest  of  the  Ilium.  5,  Surface  of  the  Gluteus 
Medius.  6,  Surface  for  the  Gluteus  Minimus. 
7,  Surface  for  the  Gluteus  Maximus.  8,  Anterior 
Superior  Spinous  Process.  9,  Anterior  Inferior 
Spinous  Process.  10,  Posterior  Superior  Spin- 
ous Process.  It,  Posterior  Inferior  Spinous 
Process.  12,  Spine  of  the  Ischium.  13,  Greater 
Sacro-Sciatic  Notch.  14,  Lesser  Sacro-Sciatic 
Notch.  15,  Tuber  Ischii.  16,  Ascending  Ramus 
of  the  Ischium.  17,  Body  of  the  Pubis.  18,  Ra- 
mus of  the  Pubis.  19,  Acetabulum.  20,  Thyroid 
Foramen. 


An  Anterior  View  of  the  Femur  o 
the  Right  Side.  1,  Depression  f<;r 
the  Round  Ligament.  2,  The  Head. 
3,  The  Neck.  4,  Trochanter  Major. 
5,  Trochanter  Minor.  6,  Surface  for 
the  Capsular  Ligament.  7,  Shaft  of 
the  Bone.  8,  The  External  Condyle.  9,  The  Internal 
Condyle.  10,  Surface  for  the  Patella. 


The  Pubis  is  the  most  central  and  anterior  portion.  These 
three  divisions  unite  at  the  point  known  as  the  acetabulum  or 
receptacle  for  the  head  of  the  femur,  which  is  a perfect  hemi- 
spherical cup  lined  with  cartilage. 

139.  Tlie  Femur. — The  Femur  is  nearly  two  feet  in  length, 
and  consequently  the  longest  bone  in  the  body,  commonly 
known  as  the  Thigli  Bone.  At  its  upper  portion  it  makes  a 

189.  What  is  tlio  average  length  of  the  Femur?  Give  its  general  features.  What  ii 
the  longest  bone  in  the  bo'dy  ? 


' A PHYSIOLOGY. 


G3 


sudden  bend  inwards,  forming  the  neck  of  the  bone,  the  ter- 
mination of  which  is  hemispherical,  in  order  to  articulate  with 
the  innominatum,  forming  the  ball  and  socket  joint.  Its 
lower  extremity  has  two  large  condyles  or  processes,  for  the 
purpose  of  giving  attachments  to  the  ligaments  of  the  knee, 
and  articulating  with  the  tibia. 

140.  The  Patella  — Or  Knee  Pan  is  the  si. 

largest  sesamoid  bone  in  the  body.  It  arti- 
culates with  the  femur,  and  lies  imbedded  in 
the  extensor  tendon  of  the  thigh.  The  chief 
value  of  this  bone  is  to  give  a change  of 
direction  to  the  force  of  the  muscles  which 
move  the  lower  bones  of  this  extremity  we 
are  now  describing.  Patella  in  Latin  signi-  AnteLrTicvv  of 
fies  a plate, and  hence  the  name  of  this  tiiePateiia.  i,  2,  sm- 

_ , TIT  face  for  the  Quadriceps 

bone,  because  ot  its  rounded  outline.  Femoris  Tendon.  3, 

Lower  Extremity  and 

141.  The  Tibia. — That  portion  of  the  Point  of  Oriitin  of  the 

, *,11  11  1 • 1 • LigaTnentiim  Patellai. 

lower  extremity  below  the  knee,  which  is 
properly  the  leg,  has  two  bones  called  crural  for  its  frame- 
work. The  largest  of  these  is  the  Tibia  (Fig.  82,  p.  64.)  It 
is  somewhat  triangular  in  its  general  outline,  having  its 
upper  extremity  depressed  in  two  places  for  the  reception 
of  the  condyles  of  the  femur.  Besides  the  femur  above, 
it  articulates  with  the  fibula  and  astragalus  below.  The 
name  tibia  is  given  to  the  bone,  since  it  resembles,  though 
remotely,  the  ancient  Phrygian  flute. 

142.  The  Fibula. — The  Fibula  is  the  other  bone  of  the 
leg,  long  and  slender.  It  articulates  at  each  end  with  the 
tibia.  The  meaning  of  the  Latin  fibula^  is  a ^^pin,’’  or 
fastening  of  a clasp,  owing  to  its  slender  form.  The  lower 
extremity  of  this  bone,  and  also  that  of  the  tibia,  forms  what 


140.  Describe  the  Patella  or  Knee  Pan.  In  what  is  it  imbedded?  141.  What  is  the 
Leg?  What  are  the  two  bones  of  it?  Which  is  the  largest  and  consequently  most  im- 
portant one  ? 142.  Give  the  general  description  of  the  Fibula.  What  compose  the  ex- 
ternal and  internal  Malleoli  ? 


G4 


II  I T C IT  O O C K ’ S ANA  r O M V 


Fig.  82.  Fig.  8?>. 


Eight  Tibia  and  Fibula.  1,  Tibia.  2 Avith  the  Naviculare.  3,  The  Os  Cub-is. 

and  3,  Inner  and  Outer  Tuberosity.  4,  4,  Naviculare,  or  Scai)hoides.  5,  The  In- 

Spinous  Process.  5,  Tubercle  for  attach-  ternal  Cuneiform.  6,  Tlie  Middle  Cunei- 

inent  of  Muscles  of  the  Thigh.  6,  Edge  of  form.  7,  The  External  Cuneiform.  8, 

Tibia.  8,  Internal  Ancle.  9,  The  Fibula.  The  Cuboid  Bone.  9,  9,  Metatarsal  Bones. 

10  and  11,  Extremities  of  Fibula.  10,  First  Phalanx  of  the  Big  Toe.  11,  Sec- 

ond Phalanx  of  the  Big  Toe.  12,  12,  13, 
13,  14,  14,  The  First,  Second  and  Third  Phalanges  of  the  other  Toes. 


arc  known  as  the  external  and  internal  malleolus,  or  the  two 
long  projections  on  each  side  of  the  ancle. 

143.  The  Tarsus. — The  Tarsus  is  made  up  of  seven  ir- 
regular bones,  forming  the  instep  of  the  foot.  The  Astra- 
galus is  of  a cubical  form  (so  named  from  its  resemblance 
to  the  die,  used  in  games  of  chance)  and  supports  the  tibia 
alone.  The  Os  Calcis,  meaning  tlic  bone  of  the  heel,  is  the 
largest  of  the  bones  of  the  tarsus,  and  is  irregularly  cubical 

143.  TIow  many  bones  rnako  up  the  Tarsus?  Why  is  the  uppermost  called  the  Astra- 
galus ? Which  is  the  largest  of  these  bones? 


AND  PHYSIOLOGY. 


C5 


in  form,  making,  by  a decided  projection,  the  heel.  Directly 
beneath  and  anterior  to  the  last  two,  are  found  the  Cuboid 
(cube-shaped)  and  the  Scaphoid  (boat-shaped),  and  anterior 
to  these  the  three  Cuneiform  (wedge-shaped),  articulating 
with  the  metatarsal  bones  in  front. 

144.  Metatarsal  Bones. — These  are  five  in  number,  and 
correspond  with  those  in  the  metacarpus,  except  that  the  one 
in  the  first  toe  is  of  equal  length  with  the  others,  and  does  not 
admit  of  so  free  motion  as  that  of  the  thumb. 

145.  The  Phalanges. — The  Phalanges  of  the  foot  are  also 
like  those  of  the  hand,  except  that  in  the  foot  the  first  row  is 
the  longest,  while  in  the  hand  it  is  in  the  third  row  or  second 
finger. 

146.  Sesamoid  Bones. — Besides  the  bones  already  men- 
tioned, there  are  frequently  found  in  stout  adult  men  small 
bones,  or  portions  of  bony  matter  called  Sesamoid  Bones, 
from  their  resemblance  to  the  Sesamum,  a kind  of  bean. 
And  although  they  are  not  constant  either  in  individuals,  or 
in  the  same  places  in  the  individual,  yet  anatomists  are 
accustomed  to  reckon  eight,  or  four  pairs  as  the  normal 
number.  They  are  all  found  enclosed  in  tendons,  and  serve 
like  the  patella  to  change  the  direction  of  motion.  They 
are  found  at  the  point  where  the  tendon  glides  over  the 
joint  made  by  the  phalanges  and  metatarsus  of  the  foot, 
and  the  metacarpus  of  the  hand,  in  the  tendon  which  plays 
over  the  under  surface  of  the  cuboid  bone  in  the  foot ; and 
also  in  the  tendons  that  glide  over  the  lower  condyles  of 
the  femur. 

147.  Bones  of  the  Ear. — In  the  Ear  are  three  bones 
which  will  be  more  appropriately  described  with  the  organ 
itself. 

148.  Number  of  Bones.  Single  Bones.— Of  the  246 


144.  How  many  Metatarsal  Bones ? 145.  How  many  Phalanges  of  the  Foot?  How 

do  they  differ  from  those  of  the  hand  ? 146.  Describe  Sesamoid  Bones.  How  many  are 
there,  and  where  are  they  generally  found  ? 147.  How  many  hones  of  the  Ear  ? 


CG 


IT  I T C II  C O C K ’ S ANATOMY 


bones  found  in  the  human  body,  all  but  thirty-four  are  found 
in  pairs,  or  one  upon  each  side  of  the  body.  The  single 
bones  are  the  frontal,  occipital,  ethmoid,  sphenoid,  vomer, 
mandible,  hyoid,  sternum,  twenty-four  vertebrae,  the  sa- 
crum and  the  coccyx. 


SYNDESMOLOGY. 

DESCRIPTION  OP  THE  LIGAMENTS. 

149.  Kinds  of  Articiilntion. — The  modes  or  manner  of 
connection  between  the  different  bones  of  the  body  are  three  : 
Synarthrosis,  Amphiarthrosis,  and  Diarthrosis.  The  first  of 
these  modes,  means  the  joining  of  such  bones  as  have  no 
motion  between  them  ; the  second,  a joint  with  the  aptitude 
for  movement  between  the  immovable  synarthrosis  on  the  one 
hand,  and  the  movable  diarthrosis  on  the  other ; the  third,  a 
movable  articulation,  which  constitutes  by  far  the  greater 
part  of  the  joints  of  the  body. 

150.  Sutura,  llarmonia,  Schindylesis,  Gompliosis. — Of 
Synarthrosis  there  are  four  varieties  : first,  Sutura,  the  ar- 
ticulation between  the  bones  of  the  skull  by  ragged  inter- 
locking edges  ; second,  Harmonia,  that  between  the  two  upper 
maxillaries,  where  the  bones  with  comparatively  straight 
edges  are  simply  placed  edge  to  edge ; third,  Schindylesis,  or 
the  joint  between  the  vomer  and  sphenoid,  where  the  ex- 
panded edge  of  one  bone  is  fitted  into  a corresponding  groove 
in  the  other ; fourth,  Gompliosis,  the  articulation  of  the  teeth 
with  the  jaws,  and  so  named  since  it  resembles  the  manner 
in  which  a common  nail  is  driven  into  a plank. 

118.  How  many  bones  in  tlio  buman  body  are  found  in  pairs?  Give  the  names  of  the 
nnrnated  bones.  140.  How  many  modes  of  connecting  the  bones  together?  Describe 
each.  150.  Give  t)ie  peculiarities  of  Sutura,  of  Harmonia,  of  Schindylesis,  and  of  Gom- 
phosis.  Give  an  example  of  the  latter. 


AND  PHYSIOLOGY. 


67 


151.  Symphyses. — Of  Amphiarthrosis  there  is  but  one 
hind,  the  Symphyses,  or  the  apposition  of  two  bones  with 
simply  cartilage  between.  Examples  of  this  are  the  arti- 
culations of  the  vertebrae,  and  the  ossa  pubis. 

152.  Arthrodia,  Giaslymus,  Eiiartlirosis. — Of  Diarthro- 
sis there  are  three  v:  rieties : Arthrodia,  Ginglymus,  and  En- 
arthrosis.  Arthrodia  is  a slightly  movable  joint,  as  of  the 
wrist  and  ancle  bones,  or  the  radius  and  ulna.  Ginglymus 
is  the  common  hinge  joint,  where  the  degree  of  movement 
is  very  considerable,  but  only  in  two  directions.  The  best 
example  of  this  is  in  the  knee.  Enarthrosis  is  the  ball  and 
socket  joint,  that  admits  of  movement  in  all  directions.  The 
only  cases  of  this  articulation  are  in  the  shoulder,  hip,  and 
thumb. 

153.  Anatomy  of  the  Articulations. — In  synarthrosis 
there  is  simply  a membrane  interposed  between  the  two  bones 
which  keeps  them  in  their  places.  In  amphiarthrosis  the 
two  extremities  are  partly  covered  with  cartilage,  lined  by 
synovial  membrane,  and  partly  connected  by  the  interosseous 
ligaments,  or  by  an  elastic  fibro-cartilage  which  adheres  to 
both  edges  of  the  bones.  In  diarthrosis  especially,  as  it  is 
exhibited  in  ginglymus,  the  general  outline  of  the  bone  is 
quadrilateral,  upon  each  edge  of  which  is  found  a ligament. 
The  lateral  ones,  however,  are  the  main  supports  of  the  joint, 
while  the  anterior  and  posterior  ones  are  thin  and  a part  of 
the  time  loose,  which  are  only  of  service  to  determine  the 
amount  of  movement  in  the  joint.  An  example  of  this  is 
seen  in  the  fingers,  since  they  can  only  be  extended  so  as 
to  lie  in  the  axis  of  the  metacarpal  bones.  The  reason 
why  they  can  not  be  bent  back  upon  the  dorsal  surface  o? 
the  hand  is  that  the  anterior  ligament  does  not  admit  of  sufii- 


151.  Describe  the  Symphyses.  Give  an  example,  152.  Give  the  three  varieties  of  Diar- 
throsis. Give  an  example  of  Arthrodia,  Ginglymus,  and  Enarthrosis.  153.  What  are 
the  component  parts  of  the  different  articulations?  Give  the  mode  of  articulation  of 
the  fingers.  Why  can  not  the  finger  bo  bent  upon  the  back  of  the  hand? 


G8 


HITCHCOCK’S  A K A T O .AI  Y 


cient  movement  in  that  direction.  In  the  knee,  liowevcr, 
there  are  thirteen  ligaments. 

154.  Motions  of  the  Joints. — The  motions  of  the  joints 
may  be  comprised  under  four  principal  divisions  : Gliding, 
Angular  movement,  Circumduction,  and  Rotation. 

155.  Gliding. — Gliding  movement  is  where  the  bones 
simply  slip  over  one  another  in  the  movement  of  the  joint, 
and  exists  to  a greater  or  less  extent  in  all  the  joints. 

156.  Angular. — Angular  movement  may  be  performed 
in  four  directions  : forwards  and  backwards,  called  flexion 
and  extension,  and  inwards  and  outwards,  called  adduction 
and  abduction.  A joint,  as  the  finger,  is  said  to  be  flexed 
Avhen  it  is  bent  upon  itself,  that  is  upon  the  palm  of  the 
hand,  and  extended  when  it  is  stretched  to  its  fullest  extent, 
or  as  in  the  finger,  when  it  is  made  straight  with  the  bones  of 
the  fore-arm.  Adduction  means  the  bringing  of  one  of  the 
extremities  towards  the  body,  or  its  fellow,  while  abduction 
has  the  reverse  signification. 

157.  Circumduction. — Circumduction  can  be  performed 
only  by  the  ball  and  socket  joints.  It  consists  in  carrying 
the  limb  about  the  joint  in  a circular  plane,  or  in  other 
words,  describing  a circle  about  the  joint  as  a center. 

158.  Rotation. — Rotation  is  the  movement  of  a bone  upon 
its  own  axis.  A slight  rotatory  movement  can  be  efiected  in 
the  joints  of  the  shoulder  and  hip,  but  the  best  instance  is 
that  of  the  radius  rotating  against  the  articular  head  of  the 
humerus,  producing  the  subdivisions  pronation  and  supina- 
tion. Pronation  consists  in  rotating  the  fore-arm  so  that  the 
palm  of  the  hand  shall  bo  downwards,  and  Supination  the 
reverse.  Rotation  is  also  observed  in  the  movement  of  the 
atlas  upon  the  pivot  of  the  axis. 


Whjit  an*  tlio  four  itiotions  of  tlio  joints  ? in.*).  Describe  the  Gliding  movement, 
l.nf).  In  wlmt  f<»nr  directions  can  Angular  movements  bo?  I.IT.  What  is  Circumduction? 
1.53.  Describe  notation.  What  is  Ib-onation  and  Supination? 


AND  PHYSIOLOGY 


69 


159.  Structure  of 
liigaments.  Ar- 
rangement of  Liga- 
ments. Capsular 
ligament.  Round 
Ligam  ent. — The 
bones  are  firmly 
bound  together  by 
ligaments.  These 
are  for  the  most 
part  bands  of  white 
glistening  fibres,  as 
firm  as  steel,  which 
are  composed  of 
white  fibrous  tis- 
sue. They  are  gen- 
erally very  short, 
and  attached  only 
to  the  enlarged  ex- 
tremities of  the 
bone.  In  most  of 
the  joints,  and  es- 
pecially the  gingly- 
mus,  the  ligaments 
are  arranged  in  a 
cross  shape  upon  the 
sides  of  the  bones, 
so  that  one  bone  may 
glide  freely  over  the 
extremity  of  an- 
other, as  one  half 
of  a door  hinge 
moves  upon  its  other 
half  In  other  in- 
stances the  ligament 
surrounds  the  w^hole 


Fia.  84. 


A magnified  View  of  a Vertical  section  of  Cartilago 
from  a new-born  Rabbit,  showing  the  progress  towards 
ossification.  1,  The  Ordinary  appearance  of  Tempo- 
rary Cartilage.  1',  The  same,  more  highly  magnified. 
2,  The  Primary  Cells  beginning  to  assume  the  linear 
direction.  2',  The  same,  more  highly  magnified.  3» 
The  Ossification  is  extending  in  the  intercellular 
spaces,  and  the  rows  of  cells  are  seen  resting  in  the 
cavities  so  formed,  the  Nuclei  being  more  separ- 
ated than  above.  S',  The  same,  magnified  more 
highly. 


TO 


HITCHCOCK’S  ANATOMY 


Fig.  85. 


An  Anterior  View  of  tbo  Ligaments  of 
the  Pelvis.  1,  The  Lower  part  of  the  An- 
terior Vertebral  Ligament  2,  The  Sacro- 
Vertebral  Ligament.  3,  The  Ilio-Lumbar 
Ligament.  4,  The  Anterior  portion  of  the 
Sacro-Iliac  Ligament  5,  The  Obturator 
Ligament  6,  Poupart’s  Ligament.  7,  That 
portion  of  the  same  which  is  known  as 
Gimbernat’s  Ligament.  8,  The  Capsular 
Ligament  of  the  Ilip-Joint  9,  The  Ac- 
cessory Ligament  of  the  Hip-Joint 


Fig.  8G. 


Ligaments  from  Shoulder-Joint.  1,  The 
Superior  Acromio-Clavicular  Ligament. 
2,  The  Coraco-Clavicular  Ligament  3, 
The  Coraco- Acromial  Ligament  4,  The 
Coracoid  Ligament.  5,  The  Capsular  Liga- 
ment of  the  Shoulder-Joint  6,  The  Liga- 
mentum  Adscititium,  or  Coraco-IIumeral 
Ligament.  7,  The  Tendon  of  the  Long 
Head  of  the  Biceps  Muscle,  issuing  from 
the  Capsular  Ligament. 


joint,  making  it  a shut  sac,  thus  performing  the  double  oflSice 
of  keeping  the  two  ends  in  contact,  and  of  holding  the  lubri- 
cating fluid  in  the  joint.  In  addition  to  these,  there  is  in 
the  ball  and  socket  joint  another  kind  of  ligamentous  attach- 
ment between  the  two  bones,  called  the  round  ligament,  or 
Ligamentum  Teres.  This  is  a bundle  of  ligamentous  fibres 
in  the  form  of  a cord,  which  is  inserted  into  the  summit  of 
the  rounded  head  of  the  bone,  and  also  in  the  bottom  of  the 
cup-shaped  cavity  that  receives  the  head.  This  is  somewhat 
lax  ordinarily,  but  not  so  much  so  but  that  it  keeps  the  head 
from  slipping  out  of  its  socket,  and  at  the  same  time  allows 
the  most  perfect  freedom  of  motion. 

l.";!).  Wh.'it  arc  the  Ligamcntfi  ? 'J’o  wliat  part  of  tho  bones  are  they  generally  at- 
tacliedl'  How  are  they  arranged  in  Ginglyinus  joints?  Why  are  they  sometimes  found 
111  Lho  form  of  a shut  sac?  Describe  the  round  ligament. 


AND  niYSIOLOGY. 
Fig.  87. 


n 


Fig.  88. 


A Lateral  View  of  the  Ligaments  of  the  Ilip- 
Joint  and  Pelvis.  1,  The  Posterior  Sacro-IIiac 
Ligament  of  the  Pelvis.  2,  The  greater  Sacro- 
Sciatic  Ligament.  3,  The  Lesser  Sacro-Sciatic 
Ligament.  4,  The  Greater  Sacro-Sciatic  Notch. 
.5,  The  Lesser  Sacro-Sciatic  Notch.  6,  The  Co- 
tyloid Ligament  around  the  Acetabulum.  T, 
The  Ligamentum  Teres.  8,  The  Line  of  At- 
tachment of  the  Capsular  Ligament  of  the  Hip- 
Joint,  posteriorly.  The  Ligament  has  been 
removed,  in  order  to  show  the  Joint.  9,  The 
Obturator  Ligament. 


The  Bight  Knee-Joint  laid  open. 
1,  The  Lower  End  of  the  Femur  cov- 
ered by  its  Articular  Cartilage.  2,  The 
Anterior  Crucial  Ligament.  3,  The 
Posterior  Crucial  Ligament.  4,  The 
Transverse  Fasciculus  adhering  to 
the  Semilunar  Cartilages.  5,  The 
Point  of  Attachment  of  the  Ligamen- 
tum Mucosum,the  rest  of  it  has  been 
removed.  6,  The  Internal  Semilunar 
Cartilage.  7,  The  External  Semilunar 
Cartilage.  8,  A part  of  the  Ligamen- 
tum Patellae  turned  downwards.  9, 
Its  Bursa  laid  open.  10,  The  Supe- 
rior Peroneo-Tibial  Articulation.  11, 
The  Interosseous  Ligament. 


160.  Aid  of  Atmospheric  Pressure. — Atmospheric  pres- 
sure also  helps  to  keep  the  bones  together.  For  since  the 
projection  of  one  member  so  accurately  fits  the  depression  in 
the  other,  and  as  the  lubricating  fluid  makes  the  coupling 
most  perfect,  the  pressure  of  the  atmosphere  assists  not  a 
little  to  keep  the  parts  together. 


161.  Inter-articular  Cartilage. — Another  arrangement  in 
the  joints  is  not  a little  singular,  and  well  adapted  to  its  pur- 
pose. This  is  an  interarticular  cartilage  in  the  knee  called 
semilunar,  or  a small  disc  of  cartilage  which  lies  loosely  bo- 

IGO.  What  besides  the  ligaments  helps  to  keep  the  bones  together  ? ICl.  Describe  the 
interarticular  cartilage  and  its  use. 


4 


72 


HITCHCOCK’S  ANATOMY 


Eig.  89. 


A View  of  the  Articulation  of  the  Lower 
Jaw,  given  by  sawing  through  the  Joint. 
1,  The  Glenoid  Fossa.  2,  The  Tubercle 
for  the  Condyle  in  its  Forward  iiiove- 
inents.  8,  The  Inter- Articular  Cartilage. 
4,  The  Superior  Synovial  Cavity.  5,  The 
Inferior  Synovial  C.avity.  6,  The  Inter- 
Articular  Cartilage  removed  from  the 
Joint  and  seen  from  below. 


Fig.  90. 


An  Anterior  View  of  the  Ligaments  of 
the  Vertebrfe  and  Ribs.  1,  The  Anterior 
Vertebral  Ligament.  2,  The  Anterior  Costo- 
vertebral Ligament.  3,  The  Internal 
Transverse  Ligament.  4,  The  Inter-Ar- 
ticular  Ligament,  connecting  the  Head 
of  the  Rib  to  the  Inlervertcbral  Sub- 
stance. 


tween  the  bones.  The  design  of  it  is  to  distribute  the  fric- 
tion over  a larger  surface,  as  well  as  to  diminish  it. 


Fig.  91. 


162.  In  Fig.  90  we  see 
the  mode  of  attachment  be- 
tween the  vertebrae  and  ribs 
which  is  that  of  three  dis- 
tinct ligaments  to  each  rib, 
besides  one  common  to  each 
pair  of  ribs.  Fig.  91  shows 
the  anatomy  of  the  elbow- 
joint.  Here  are  no  less 
than  four  distinct  ligaments. 
We  see  in  Fig.  92  the  liga- 

An  Internal  View  of  the  Elbow- Joint. 
1,  The  Capsular  Ligament.  2,  2,  The  In- 
ternal Lateral  Ligament.  3,  The  Coro- 
nary Ligament.  4,  The  Ligamentum  Te- 
res. 5,  The  Interosseous  Ligament.  6, 
The  Internal  Condyle,  which  conceals  tho 
Capsular  Ligament  behind. 


1C2.  Describe  tho  ligaments  in  Figs.  90,  91,  92  and  93.  163.  How  are  the  joints  lubri- 

cated ? 


AND  PHYSIOLOGY 


IS 


merits  'which  unite  the  lower 
end  of  the  fibula  to  the  tibia 
and  the  tarsal  bones,  and  in 
Fig.  93  the  ligaments  of  the 
foot, 

163,.  Synovial  Membrane 
and  its  Secretion.  — The 
lubrication  of  the  joints  is 
effected  by  means  of  a thin 
membrane  lining  their  cavi- 
ties which  secretes  an  oily 
substance  called  the  Synovia, 
(Fig.  94,  p.  74),  that  is  con- 
stantly applied  to  the  oppos- 
ing surfaces.  In  health  the 
action  of  the  joint  stimulates 
this  membrane  to  the  secre- 
tion of  a proper  amount  of 


A Posterior  View  of  the  Ankle-Joint  of 
the  Left  Side.  1,  The  Interosseous  Liga- 
ment of  the  Bones  of  the  Leg.  2,  The 
Posterior  Inferior  Ligament  connecting 
the  Tibia  and  Fibula.  3,  The  Transverse, 
or  Long  Fibres  of  the  same  Ligament 
4,  The  Internal  Lateral  Ligament.  5,  The 
Posterior  Fasciculus  of  the  External  Lat- 
eral Ligament.  6,  The  Middle  Fascicu- 
lus of  the  same.  7,  The  Synovial  Capsule 
8,  The  Os  Calcis. 


Fig.  93. 


13  bl-  II 


A Vertical  Section  of  the  Ankle-Joint  and  Foot  of  the  Right  Side.  1,  The  Tibia, 
2,  The  Astragalus.  3,  Os  Calcis.  4,  The  Scaphoides.  5,  The  Cuneiforme  Internum. 
6,  The  Metatarsal  Bone  of  the  Great  Toe.  7,  The  First  Phalanx  of  the  Great  Toe. 
8,  The  Second  Phalanx  of  the  Great  Toe.  9,  The  Articular  Cavity  between  the  Tibia 
and  Astragalus,  with  its  Articular  Adipose  Matter.  10,  The  Synovial  Capsule  between 
the  Astragalus  and  Calcis.  11,  The  Calcaneo-Astragalian  Interosseous  Ligament. 
12,  The  Synovial  Capsule  between  the  Astragalus  and  Scaphoides.  13,  The  Calcaneo- 
Scaphoid  Ligament.  14,  The  Calcaneo-Cuboid  Ligament.  15,  The  Synovial  Capsule 
between  the  Scaphoides  and  Cuneiforme  Internum.  16,  The  Synovial  Capsule  between 
the  Cuneiforme  Internum  and  the  First  Metatarsal  Bone.  17,  Tlie  Metatarso-Pha- 
langial  Articulation  of  the  Great  Toe,  with  the  Sesamoid  Bones  below,  18,  The  Pha- 
l.ingial  Articulation  of  the  Great  Toe. 


HITCHCOCK’S  ANATOMY 


74 


Fig.  94. 


An  Internal  View  of  the  Ankle-Joint  of 
the  Kight  Side.  1,  Internal  Malleolus. 

2,  2,  Part  of  the  Astragalus,  tae  rest  being 
concealed  by  Ligaments.  3,  Os  Calcis.  4, 
Scaphoides.  5,  Internal  Cuneiform  Bone. 

G,  Internal  Lateral,  or  Deltoid  Ligament. 

7.  The  Synovial  Capsule,  covered  by  a few 
Fibres  of  a Capsular  Ligament.  8,  Tendo  A 
between  this  Tendon  and  the  Tuberosity  of 


synovia,  the  superabundance 
of  which  (when  it  is  present) 
is  removed  by  the  absorb- 
ent vessels.  This  lubricating 
fluid,  however,  is  not  poured 
out  directly  upon  the  ends 
of  the  bones,  but  upon  smooth 
and  elastic  cartilage,  which 
is  found  in  every  joint,  not 
only  for  furnishing  a smooth 
articular  surface,  but  also  to 
diminish  the  force  of  jars  by 
its  clastic  character. 

diillis.  A small  Bursa  is  seen 

tho  Os  Calcis. 


FUNCTIONS  OR  USES  OF  THE  BONEg. 

164.  The  uses  of  the  bones  may  be  classed  under  three 
divisions  : 

First,  for  a framework  to  the  whole  system. 

Second,  to  furnish  points  of  attachment  to  muscles  and 
ligaments. 

Third,  to  protect 'the  softer  parts. 

165.  A Framework.  Ligaments  used  as  Braces  and  Pins, 
— Exactly  as  a human  architect  plans  and  constructs  a frame 
to  the  house,  so  the  Great  Architect  has  formed  the  bones. 
Each  bone  is  fitted  exactly  to  the  position,  size,  and  use  of 
the  part  where  it  is  placed,  and  nowhere  can  a supernumerary 
bone  be  found.  In  the  house  to  be  built,  braces  and  joining 
pins  must  be  employed,  and  those  generally  of  a tougher 
material  than  tho  frame  itself.  So  in  the  human  body,  liga- 

AVliy  is  cartilage  useful  in  the  lubrication  of  Joints?  IGL  Give  the  uses  of  the  bones 
as  classed  above.  105.  Compare  the  boues  and  ligaments  with  tho  timbers,  braces  and 
]iius  of  a house. 


AND  PHYSIOLOGY. 


'i’a 

ments  and  cartilage  exist  wherever  two  opposite  extremities 
need  strength  and  support  to  keep  them  in  their  places.  In 
the  railway  locomotive  immense  strength  is  required,  and  at 
the  same  time  perfect  freedom  of  motion  in  certain  positions, 
all  of  which  is  effected  by  the  ponderous  bars,  levers  and 
wheels,  perfectly  secured  by  bolts,  keys  and  screws.  But  in 
the  human  frame  by  how  much  more  simple  means  is  the 
same  end  secured.  No  angular  or  cylindrical  couplings 
secure  the  human  joints,  though  beautifully  adapted  to  pro- 
duce movement  in  every  direction,  and  no  attention  or  care  is 
necessary  to  lubricate  and  preserve  in  ^ good  condition  the 
working  parts  of  this  machine,  but  a few  tough  fibers  and 
membranes,  secure  at  once  in  a most  perfect  manner  every 
portion  of  the  frame,  and  provide  at  the  same  time  means  for 
its  lubrication. 

166.  Use  of  the  Anomalous  Forms  of  Bones. — The  bones 
are  fitted  for  the  attachment  of  muscles  and  ligaments. 
Hence  it  is  that  they  are  of  such  anomalous  and  curi- 
ous forms,  apparently  constructed  without  design  or  pur- 
pose. But  as  we  study  them,  and  understand  the  various 
motions  which  they  must  perform,  as  well  as  the  organs 
which  many  of  them  must  protect,  or  provide  space  for,  we 
find  that  it  is  impossible  to  improve  in  the  slightest  degree  on 
the  construction  of  the  skeleton.  The  size,  the  form,  the 
quality  of  material,  the  exact  position  of  every  process,  curve 
and  foramen  of  the  bones,  and  the  manner  in  which  all  are 
arranged,  are  most  wisely  adapted  to  their  functions  and  to 
the  happiness  of  the  vertebrated  race. 

167.  Reason  why  the  long  Bones  are  Tubes. — In  this 
connection  should  be  mentioned  the  reason  why  the  long 
bones  are  hollow.  It  is  for  the  same  cause  that  the  stems  of 
grasses,  grains,  and  many  other  vegetables  are  hollow  cylin- 
ders, instead  of  solid  rods  : to  secure  great  strength  with  as 

166.  Why  are  the  bones  of  such  peculiar  shapes  ? 167.  Give  the  reason  why  many  of 
the  bones  are  hollow. 


76 


HITCHCOCK’S  ANATOMY 


little  material  as  possible.  For  example,  were  the  liuman 
femur  a solid  rod,  instead  of  a hollow  cylinder,  as  it  now  is, 
it  would  require  a bone  twice  the  diameter  of  the  present  one 
to  be  sufficiently  strong  for  the  purposes  required  of  it. 
Hence  were  the  whole  skeleton  constructed  on  this  principle, 
it  Avould  be  so  cumbersome  and  heavy  that  it  would  require  a 
larger  amount  of  muscle,  making  the  body  unwieldy,  and 
thus  deprive  it  of  its  rapid  and  easy  motion. 

168.  Protection  given  to  the  Brain.  Use  of  the  Diploc. 
Reason  for  several  Bones  in  the  Skull The  bones  af- 

ford much  protection  to  all  the  enclosed  and  adjacent  or- 
gans. In  the  bones  of  the  head,  for  example,  how  perfect 
the  guard  over  the  nervous  center.  Here  arc  three  means 
for  protection,  two  plates  of  bone,  and  an  intervening  cel- 
lular space.  The  outer  table  being  very  tough  presents 
a substance  somewhat  yielding  to  blows  inflicted  by  pointed 
substances,  and  even  if  the  blow  be  so  severe  as  to  cause 
fracture,  this  can  not  extend  so  far  as  in  a hard  and 
brittle  material.  And  the  intervening  space  or  diploc  very 
materially  deadens  the  force  of  any  shock  given  to  the 
outside  of  the  head,  precisely  as  the  springs  of  a carriage 
prevent  the  unevenness  of  the  road  from  giving  the  same 
sudden  jolt  to  the  body  that  is  communicated  to  the  wheels. 
The  inner  table  is  necessarily  brittle,  since  the  brain  de- 
mands the  firmest  possible  support.  But  why  is  the  skull 
made  up  of  several  bones  instead  of  one  ? In  the  first  place  a 
more  symmetrical  growth  can  be  effected,  provided  the  points 
of  increase  are  numerous,  and  especially  so  since  in  early  life, 
while  the  growth  is  going  on,  there  is  a thin  layer  of  cartilage 
between  the  edges  of  each  bone,  thus  allowing  all  necessary 
motion;  secondly,  because  a fracture  can  not  extend  furthei 
than  a suture,  as  all  the  vibrations  are  overcome  by  the  inter- 
position of  any  soft  substance  like  cartilage.  And  for  this 

lOS.  llow  do  tlio  l)onos  afford  a protection  to  the  softer  parts?  What  is  tho 
use  of  tho  dipl66  in  tho  hones  of  tho  skull?  Stuto  tho  reason  of  several-  hones  in 
tho  skull. 


AND  PHYSIOLOGY. 


77 


reason  the  jar  of  any  blow  is  greatly  lessened  by  the  same 
cause. 

169.  Use  of  the  Ribs. — Again  we  see  the  bones  of  the 
thorax  arranged  for  the  protection  of  the  enclosed  organs. 
Within  this  cavity  are  organs  delicate  and  easily  destroyed, 
but  which  require  elastic  and  movable  walls.  The  elasticity 
is-  easily  gained  by  the  cartilaginous  portion  of  the  ribs  at- 
tached to  the  sternum,  which  yields  considerably  upon  pres- 
sure ; and  the  motion  and  consequent  enlargement  is  effected 
by  the  oblique  position  of  the  ribs,  as  they  run  downwards 
and  forwards  from  their  articulation  with  the  vertebrae.  As 
the  vertebral  extremity  is  the  fixed  point,,  of  course  the  eleva- 
tion of  the  sternal  end  will  enlarge  the  cavity  of  the  thorax 
antero-posteriorly.  Another  use  of  the  cartilaginous  extrem- 
ity of  the  ribs  is  to  lessen  the  chance  of  fracture.  The  tho- 
rax is  exposed  to  blows  and  falls  more  than  many  other  por- 
tions of  the  body,  and  therefore  more  exposed  to  fracture. 
For  instance,  if  a person  suddenly  falls  to  the  ground,  the 
head  by  an  instinctive  movement  is  raised,  while  the  trunk  or 
extremities  receive  the  force  of  the  shock.  Also  the  head  or 
extremities  can  by  rapid  movements  be  suddenly  removed 
from  the  contact  with  missiles,  while  the  body,  comparatively 
unwieldy,  must  meet  the  blow. 

170.  Use  of  the  Iiinomiiiata. — The  expanded  condition 
of  the  Innominatum  affords  service  and  protection  in  different 
ways.  A depression,  or  cup-shaped  cavity  is  thus  made  for 
giving  a firm  support  to  the  organs  contained  in  the  abdomen, 
as  Avell  as  a solid  foundation  to  the  spinal  column.  It  how- 
ever renders  especial  service  by  furnishing  a powerful  point 
of  attachment  for  many  of  the  muscles  both  above  and  below  : 
those  which  form  the  walls  of  the  abdomen,  and  many  of 
those  which  move  the  extremities. 

171.  Why  there  are  so  many  Bones  in  the  Spinal 


1G9^  Describe  the  uses  of  the  ribs,  and  the  reason  M’by  they  are  partly  made  up  of  car- 
tilage. Why  do  they  run  obliquely  from  the  points  of  attachment?  170.  Explain  why 
the  Innominata  are  so  broadly  expanded. 


18  HITCHCOCK’S  anatomy 

Column. — A large  number  of  bones  in  the  spinal  column  is 
necessary  in  order  to  give  flexibility  to  the  body.  Were  the 
number  considerably  less,  the  movements  of  the  trunk  would 
be  attended  with  much  more  difiiculty  than  at  present,  and  bo 
devoid  of  grace.  And  were  the  separated  vertebrm  long 
bones,  they  would  be  much  more  easily  broken,  thereby  en- 
dangering the  spinal  marrow.  Another  reason  for  the  great 
number  of  these  bones,  is  the  necessity  of  the  elastic  cartilage 
between  them,  to  protect  the  brain.  Were  the  joints  fewer, 
in  order  to  give  equal  protection  to  the  brain  from  jars,  this 
cartilage  must  of  necessity  have  been  greatly  thickened, 
thereby  weakening  the  joint,  and  injuring  it  as  a central  axis 
of  support  to  the  whole  body,  and  also  increasing  the  liabil- 
ity to  dislocations,  as  well  as  greatly  endangering  life,  by 
pressure  upon  the  spinal  cord. 

172.  Use  of  the  Clavicle. — The  value  of  the  clavicle  lies 
in  keeping  the  upper  extremity  in  its  proper  position,  so  as 
to  prevent  the  humerus  from  coming  forward  towards  the 
middle  portion  of  the  body.  By  its  direct  resistance  it  also 
assists  in  some  muscular  actions,  such  as  lifting  heavy  weights 
with  the  hands. 

173.  Need  of  two  Bones  in  the  Fore -Arm. — The  use  of 
two  bones  in  the  fore-arm,  as  already  mentioned,  is  to  pro- 
duce the  movements  of  supination  and  pronation.  And  since 
these  movements  are  of  primary  importance,  and  one  bone 
can  not  answer  this  end,  two  are  provided.  Again,  if  one  be 
fractured,  the  other  will  act  as  a splint  for  keeping  the  broken 
one  in  place,  greatly  superior  to  the  artificial  splint,  because  the 
natural  splint  needs  no  compression. 

174.  Why  several  Bones  in  the  Carpus. — In  the  carpus 
are  found  eight  bones,  and  yet  ^ye  know  there  is  but  little 
motion  between  them.  The  reason  Avhy  exactly  this  number 

171.  AVliJit  is  tho  reason  why  so  many  bones  aro  i)lace(l  in  the  spinal  column?  AVliat 
is  llio  iiso  of  tho  intervertebral  substance ? 172.  AVliat  service  does  tho  clavicle  render 

1o  the  upper  extremities?  173.  Why  are  there  two  bones  in  the  forc-arm?  174.  What 
can  be  said  of  tlie  many  bones  of  tho  carpus  ? 


AND  PHYSIOLOGY. 


V9 

is  required,  is  not  so  easily  explained,  but  it  is  evident  that 
one  bone  could  not  perform  their  function,  nor  the  prolonga- 
tion of  the  radius  and  ulna  to  the  metacarpus.  Several  bones 
are  required  in  order  to  give  easy  and  graceful  motion  to  the 
wrist,  as  well  as  strength.  One  bone  could  not  answer  the 
purpose,  since  the  very  many  oflSces,  which  the  hand  has  to 
perform,  could  not  be  effected,  unless  the  wrist  bones  were 
very  strongly  bound  together,  and  flexible  to  a certain  extent. 
The  arrangement  of  the  bones  in  two  rows  allows  a little 
movement  of  the  hand  upon  the  wTist. 

175.  Function  of  Metacarpus — The  metacarpus  of  five 
long  bones  gives  support  to  the  fingers.  They  are  long  rather 
than  short  bones,  in  order  to  give  slenderness  to  the  hand, 
and  also  to  afford  a solid  surface  for  the  fingers  to  meet  in 
the  act  of  prehension. 

176.  Need  of  three  Phalanges  to  the  Fingers,  and  two 
Phalanges  to  the  Thumb. — The  phalanges  of  each  finger  are 
three  in  number,  whilst  those  of  the  thumb  are  but  two. 
The  obvious  reason  of  this  is  to  give  greater  firmness  to  the 
thumb,  and  flexibility  to  the  fingers.  The  hand  in  man  dif- 
fers from  the  anterior  extremity  of  all  other  animals  in  the 
power  of  perfectly  opposing  the  thumb  to  each  of  the  fingers, 
which  of  course  gives  him  a great  superiority  in  all  delicate 
manipulations,  and  especially  in  grasping  minute  objects. 
And  it  is  easy  to  see  that  a third  phalanx  in  the  thumb  would 
not  only  diminish  the  firmness  of  this  member,  but  would 
render  the  hand  an  awkward  and  clumsy  organ,  instead  of  an 
instrument  beautifully  and  perfectly  adapted  to  the  multi- 
farious offices  which  it  has  to  perform. 

177.  The  great  length  of  the  lower  Extremities.  Pe-, 
culiarities  of  the  Femur. — The  value  of  the  great  length  in 
the  lower  extremities,  is  manifest  as  a means  of  rapid  pro- 

Why  would  not  one  bone  be  sufficient?  175.  The  use  of  the  metacarpus.  176.  Why 
are  there  but  two  phalanges  in  the  thumb  and  three  in  each  finger?  What  would  be 
the  effect  of  a third  phalanx  in  the  thumb  ? 177.  Why  are  the  lower  extremities  pro- 
portionally longer  than  the  upper  ? 

4^ 


80 


HITCHCOCK’S  anatomy 


gression,  and  also  for  affording  a firm  support  to  tlic  trunk 
when  engaged  in  the  various  kinds  of  labor.  Were  tiiese  ex- 
tremities much  shorter  than  they  now  are,  walking  would  not 
only  be  a tediously  slow  process,  but  a laborious  one.  The 
femur  has  some  remarkable  peculiarities.  In  the  first  place 
it  presents  in  its  articulation  with  the  innominatum  the  most 
perfect  specimen  of  a ball  and  socket  joint  in  the  system. 
Besides  this  it  bends  at  nearly  a right  angle  at  its  upper  end, 
making  what  is  called  the  neck,  and  here  it  is  that  the  frac- 
ture of  the  thigh-bone  generally  occurs.  The  use  of  this 
curvature  is  to  place  the  points  of  support  for  the  trunk  as 
far  as  possible  from  the  center  of  gravity  of  the  body,  thereby 
giving  the  body  the  most  secure  position  on  the  lower  ex- 
tremities, and  especially  for  the  attachment  of  powerful 
muscles  to  move  the  thigh  and  leg,  as  well  as  to  maintain 
securely  the  trunk  when  the  legs  are  the  fixed  points.  This 
projection  is  called  the  Trochanter  process,  and  is  spongy  or 
cellular  in  its  structure.  And  it  is  not  a little  interesting  to 
notice,  when  this  process  is  sawn  through  in  a perpendicular 
direction,  that  the  cells  are  arranged  in  an  arched  form  from 
below  upwards,  thereby  greatly  aiding  the  strength  of  the 
bone.  The  same  arrangement  is  seen  in  some  other  bones  of 
the  body,  when  they  are  in  an  exposed  position.  The  lower 
extremity  of  this  bone,  as  has  already  been  mentioned,  is 
greatly  expanded,  in  the  shape  of  two  condyles  for  the  firm 
articulation  with  the  tibia.  The  necessity  for  this  lies  in  the 
fact  that  the  knee-joint  is  one  of  the  most  exposed  joints  in 
the  whole  body,  and  the  one  which  receives  the  hardest  strain. 
The  protection  of  the  nerves  and  blood  vessels,  which  are  sent 
to  the  leg,  is  also  worthy  of  a notice.  It  is  effected  by  a 
deep  groove  between  the  condyles  on  the  backside  of  the 
leg,  which  guards  these  vessels  from  blows  in  every  direc- 
tion except  behind,  from  whence  they  are  the  least  apt  to  come. 

What  remarkable  joint  between  the  femur  and  the  innorninata?  What  is  the  ar- 
rangement of  tlio  cellular  structure  in  the  upper  part  of  the  femur?  Why  has  the  fe- 
mur so  largo  i)roces.se3  on  its  lower  extremity  ? 


AND  PHYSIOLOGY. 


81 


178.  Use  of  t li e Tarsus . — In  the  Tarsus  we  see  the  value 
of  several  bones  instead  of  one.  It  is  the  movement  of  these 
upon  one  another  that  imparts  elasticity  to  the  step  and  firm- 
ness of  support  to  the  whole  body ; and  hence  it  is  that  all 
artificial  legs  produce  a limping  motion  in  the  body.  By  no 
mechanical  contrivance  can  the  suppleness  of  the  tarsus  and 
of  the  muscular  actions  be  supplied. 

‘ 179.  Two  Bones  in  the  Great  Toe,  and  three  Bones 

in  all  the  Others . — The  great  toe  of  the  foot,  like  the  thumb 
of  the  hand,  has  only  two  phalanges.  This  is  mainly  for  the 
purpose  of  securing  greater  strength  to  the  foot  in  walking 
and  standing.  It  is  also  of  service  for  opposition  to  the  other 
toes,  as  is  seen  in  those  rare  cases  of  persons  deprived  of  their 
upper  extremities,  who  can  readily  make  use  of  the  foot  for 
many  of  the  delicate  purposes  to  which  the  hand  is  adapted, 
such  as  writing,  using  scissors,  and  placing  the  crystal  in  a 
watch.  The  remaining  toes,  like  four  of  tlie  fingers,  receive 
a tendon  only  at  the  base  of  the  second  and  third  phalanx, 
the  first  one  being  interposed  merely  to  give  strength  and 
slenderness  to  the  extremities,  as  well  as  the  power  of  sur- 
rounding objects  in  the  act  of  prehension.  The  slenderness 
of  the  fingers  above  the  toes  is  a distinguishing  characteristic 
of  man,  showing  that  the  office  of  the  foot  is  merely  to  sup- 
port the  body  on  the  ground,  and  of  the  hand  to  perform  the 
business  of  every-day  life  in  its  ten  thousand  forms. 


HYGIENIC  INFERENCES. 

180. — 1.  Reason  of  Bistorted  Bones.— In  the  early  life 
of  man  and  other  vertebrate  animals,  the  animal  portion  of 
bones  greatly  predominates  over  the  earthy  constituents,  and 
hence  they  yield  more  readily  to  pressure,  but  are  not  so 

178.  IIow  do  the  bones  of  the  Tarsns  give  elastieity  to  the  step?  179.  TIow  do  the 
phalanges  of  the  foot  compare  with  those  of  the  hand  in  number?  Why  are  the  bones  of 
the  hand  longer  than  those  of  the  foot  ? ISO.  What  kind  of  matter  predominates  in  the 
early  life  of  bones  ? 


82 


HITCHCOCK’S  ANATOMY 


liable  to  break  as  in  older  persons.  Tliis  is  the  reason  why 
falls  and  blows  so  seldom  do  much  injury  to  children.  It  is 
also  the  reason  wdiy  distortions  and  curvatures  of  some  of  the 
bones  are  so  common,  since  too  often  children  are  either  urjzcd 
or  j)crmitted  to  use  their  limbs  excessively  before  their  bones 
are  made  vsolid  by  the  deposition  of  earthy  matter.  These 
distortions  are  most  common  in  children  who  arc  weak  and 
sickly,  because  in  them  the  recuperative  powers  are  small. 

181.  — 2.  Danger  of  Constrained  and  Unnatural  Posi- 
tions in  Children, — Hence  w^e  infer  that  children  should 
not  be  confined  in  any  unnatural  or  constrained  position,  but 
allowed  to  move  freely  in  whatever  direction  nature  may  de- 
mand. And  all  punishments  of  this  sort,  inflicted  by  parents, 
guardians,  and  school  teachers  upon  young  persons,  such  as 
standing  on  one  leg,  or  holding  a book  with  an  extended  arm 
for  a long  time,  are  dangerous  and  ought  to  be  proscribed, 
since  they  are  too  often  the  cause  of  bow  legs  and  curvature 
of  the  spinal  column. 

182.  — 3.  Cause  of  the  Rickets. — The  disease  known  as 
Rickets  is  produced  by  imperfect  nutrition  of  the  bones.  This 
is  generally,  though  not  always,  the  result  of  poverty  or  vice, 
or  both  combined.  The  direct  cause  of  the  disease  is  a de- 
ficiency  of  earthy  matter  in  the  bones.  This  is  either  ab- 
sorbed or  never  produced,  and  as  a result  the  bone  is  softened^ 
and  by  the  tonicity  of  the  muscles  the  body  is  drawm  into  un- 
sightly deformity.  An  observance  of  the  laws  of  health  is 
the  best  medicine  for  this  disease. 

183.  — 4.  Need  of  Cleanliness  of  the  Teeth — Tooth  Pow- 
ders— Tooth  Picks — Decayed  Teeth — Worthless  Teeth 
should  he  E x t r a c t e d . — From  the  almost  inevitable  exposure 
of  the  teeth  to  mechanical  and  chemical  agents,  we  see  that 
they  need  considerable  care  and  attention.  They  need  to  he 

W'liy  do  falls  and  blows  seldom  injure  cliildrcn  as  they  do  adults  ? In  what  children 
are  distortions  the  most  common  ? ISl.  W^’hy  should  children  ho  unconstrained  in  their 
bodily  exercise ? W’hut  is  said  about  punishments  that  <listort  the  bones  of  children? 
1S2.  What  is  the  usual  cause  of  liickcts  ? W'hat  is  the  best  medicine  for  it  ? 1S3.  Give 
the  most  important  hygienic  rule  for  the  preservation  of  the  teeth. 


AND  PHYSIOLOGY. 


83 


ke'pt  clean.  This  can  ordinarily  be  accomplished  by  the  use 
of  a soft  tooth  brush  and  pure  water  thoroughly  applied  at 
least  once  in  the  twenty-four  hours.  A tooth-powder  of  an 
alkaline  character,  or,  what  is  the  same  thing,  clean  toilet 
soap,  can  be  occasionally  used  with  benefit.  A tooth  pick 
should  be  possessed  and  used  by  every  gentleman  and  lady 
ioo^  though  it  should  be  made  of  wood,  ivory,  tortoise-shell, 
bone,  quill,  or  some  substance  softer  than  the  tooth  itself.  If 
the  teeth  are  very  closely  set  together,  frequently  drawing  a 
thread  between  them  will  aid  in  preventing  decay.  If  any  of 
them  have  begun  to  decay,  a good  dentist  should  be  consulted 
as  soon  as  possible,  and  the  cavities  filled  with  gold,  since  ar- 
tificial teeth  can  never  be  so  valuable  as  natural  ones,  even 
though  partly  filled  with  gold.  When  teeth  are  past  filling 
they  should  be  removed,  as  they  are  the  means  of  producing 
decay  in  others,  as  well  as  many  pains  called  neuralgia. 

184.  — 5.  The  Teeth  not  to  he  Used  on  very  Hard  Sub- 
stances.— The  teeth  should  be  used  only  for  the  purposes  for 
which  they  were  designed.  The  teeth  of  squirrels,  rats,  and 
beavers  were  made  expressly  for  cutting  wood  and  gnawing 
open  nuts,  but  not  so  with  the  human  teeth.  Even  the  con- 
stant biting  of  thread,  the  holding  of  a pencil  or  tobacco-pipe 
between  the  teeth,  and  especially  the  cracking  of  nuts,  are 
practices  very  injurious,  and  often  cause  the  decay  of  these 
organs. 

185.  — 6.  Teeth  Generally  Decay  Early  in  life. — Ex- 
perience shows  that  teeth  decay  the  most  rapidly  in  the  early 
part  of  life,  generally  between  the  ages  of  fifteen  and 
thirty.  Hence  youth  need  to  take  especial  care  to  preserve 
them,  not  only  on  account  of  the  pain  and  deformity  which 
their  loss  occasions,  but  because  of  their  remote  effects  upon 
the  voice  and  especially  upon  the  digestive  organs. 

What  kind  of  tooth  powder  is  the  best  ? Who  should  use  tooth  picks  ? What  treat- 
ment should  be  given  to  decaying  and  decayed  teeth?  What  substance  alone  should 
teeth  be  filled  with?  184.  For  what  purposes  should  human  teeth  never  be  used?  185. 
In  what  period  of  life  do  teeth  decay  the  fastest?  What  are  important  reasons  for  an 
especial  care  of  the  teeth  ? 


84 


Hitchcock’s  anatomy 


186.  C]assifiC(ition  of  Animals. — The  liiglicst  mid  most 
competent  authorities  differ  widely  in  their  attempts  to  classify 
the  Animal  Kingdom  ; that  is,  to  divide  it  into  smaller  groups, 
wdiich  are  Sub-Kingdoms  or  Provinces,  Classes,  Orders,  Fa- 
milies, Genera,  and  Species.  We  have  no  room,  had  we  the 
ability,  to  decide  these  difficult  questions.  There  is,  how- 
ever, a general  acquiescence  in  the  principle  first  introduced 
by  Cuvier,  that  animals  ivere  created  on  four  great  types  or 
plans,  which  he  calls  Vertebrata,  Articulata,  Mollusca,  and 
Radiata.  The  discrepancy  lies  chiefly  in  the  subdivisions  of 
these  leading  groups.  We  shall  merely  present  the  classifi- 
cations of  two  of  the  most  eminent  living  anatomists  and  zoolo- 
gists— Professor  Louis  Agassiz  of  Cambridge,  and  Sir  Richard 
Owen  of  London — not  attempting  to  decide  between  them. 

187.  Agassiz  divides  the  whole  animal  kingdom  into  four  great  branches, 
the  same  as  those  named  above.  The  Yertebrata  he  divides  into  eight 
classes:  1,  The  Myzontes,  subdivided  into  two  orders;  2,  Fishes  proper, 
into  two  orders ; 3,  Ganoids,  into  three  orders ; 4,  Selachians,  into  three  or- 
ders; 5,  Amphibians,  into  three  orders;  6,  Reptiles,  into  four  orders;  7, 
Birds,  into  four  orders ; 8,  Mammalia,  into  three  orders. 

The  Branch  Articulata  he  divides  into  three  classes:  1,  Worms,  with  three 
orders ; 2,  Crustacea,  with  four  orders ; 3,  Insects,  with  three  orders. 

The  Branch  Mollusca  he  divides  into  three  classes:  1,  Acephala,  with 
four  orders;  2,  Gasteropoda,  with  three  orders;  3,  Cephalopoda,  with  two 
orders. 

The  Branch  Radiata  he  divides  into  three  classes:  1,  Poljrpi,  with  two 
orders ; 2,  Acalephse,  with  three  orders ; 3 Echinoderms,  with  four  orders. 

188.  Owen  calls  the  above-named  four  divisions  of  the  Animal  Kingdom, 
Provinces.  The  Province  Yertebrata  he  subdivides  into  four  classes:  1,  Mam- 
malia, with  fifteen  orders ; 2,  Aves,  or  Birds ; 3,  Reptilia,  with  fifteen  orders ; 
4,  Fishes,  with  eleven  orders.  His  fifteen  orders  of  Mammalia  are:  1,  Mono- 
tremata;  2,  Marsupialia;  3,  Rodentia;  4,  Insectivora;  5,  Cheiroptera;  6, 
Bruta;  7,  Cetacea;  8,  Sirenia;  9,  Toxodontia;  10,  Proboscidea;  11,  Peris- 
sodactyla;  12,  Artiodactyla;  13,  Carnivora;  14,  Quadrumana;  15,  Bimana. 

Tlie  Provinco  Articulata  he  divides  into  six  classes : 1,  Arachnida,  with 
four  orders ; 2,  Insects,  with  eleven  orders ; 3,  Crustacea,  with  eleven  orders ; 
4,  Epizoa,  with  three  orders ; 5,  Anellata,  with  four  orders ; 6 Cirripedia, 
with  three  orders. 

The  Mollusca  he  divides  into  six  classes:  1,  Cephalopoda,  with  two  orders; 
2,  Gasteropoda,  with  ten  orders ; 3,  Pteropoda,  with  two  orders ; 4,  Lamelli- 
branchiata,  with  two  orders  ; 5,  Brachiopoda  ; 6,  Tunicata,  with  two  orders. 


AND  PHYSIOLOGY. 


85 


The  Radiata  he  divides  into  nine  classes ; 1,  Echinodermata ; 2,  Brjozoa; 
3,  Anthozoa;  4,  Acalephse;  5,  Ilydrozoa ; G,  Ccelelmintha ; Sterelrniiitha ; 
8,  Rotifera;  9,  Polygastria. 

189.  To  the  above  Animal  Kingdom  Prof.  Owen  has  added  another  kingdom  ol 
organisms,  “ mostly  of  minute  size,  and  retaining  the  form  of  nucleated  cells, 
which  manifest  the  common  organic  characters,  but  without  the  distinctive 
superadditions  of  true  plants  or  animals.”  These  he  calls  Protozoa,  and  ar- 
ranges in  three  classes:  1,  The  Amorphozoa,  or  Sponges;  2,  the  Rhizopoda, 
which  are  the  Polythalamia,  or  Poraminifera ; 3,  the  Infusoria,  or  Animalcula 
— the  last  two  classes  being  mostly  microscopic. 


COMPARATIVE  OSTEOLOGY. 

191.  Microscopic  Structure, — In  microscopic  structure  and 
chemical  composition  the  bones  of  mammals,  including  man, 
and  of  all  vertebrates  are  essentially  the  same,  and  in  their 
general  outline  a considerable  degree  of  correspondence  can 
be  traced  between  many  of  the  bones  of  the  human  system, 
and  those  performing  similar  functions  in  the  lower  animals. 
Thus  we  almost  always  find  the  femur  to  have  a globular 
head  on  its  upper  extremity  supported  by  a neck  which  makes 
a considerable  angle  with  the  shaft,  and  the  two  large  con- 
dyles on  the  lower  extremity. 

192.  Spinal  Column  of  Mammals.  Cervical,  Dorsal, 
Lumbar,  Sacral,  Caudal  Vertebrse. — In  Mammals  the  Spinal 
Column  is  made  up  of  five  classes  of  vertebrae  : the  cervical, 
of  the  neck  ; the  dorsal,  of  the  back ; the  lumbar,  of  the  loins ; 
the  sacral,  of  the  hip  ; and  the  caudal,  of  the  tail.  The  Cervi- 
cal vertebrae,  with  but  two  or  three  exceptions  in  all  mammals, 
consists  of  seven  in  number.  The  average  number  of  the  Dor- 
sal is  thirteen,  the  Bats  having  eleven,  and  one  of  the  Sloths 


191.  What  is  the  microscopic  structure  of  the  hones  of  Mammals  ? What  about  the 
general  correspondence  in  outline,  etc.  ? Instance  the  femur.  192.  What  are  the  five 
classes  of  Vertebrae  ? How  constant  is  the  typical  number  seven  for  the  Cervical  ver- 
tebrae ? Give  the  average  number  of  the  Dorsal. 


86 


HITCHCOCK’S  ANATOMY 


Fig.  95. 


bai*  Yertebrse.  'V.  s.  Sacral  Vertebrae.  'V.  q.  Caudal  Vertebrae,  o.  Scapula,  h.  Hume- 
rus. 6*.  Ribs.  cu.  Ulna.  ca.  Carpus,  m.  c.  Metacarpus,  ph.  Phalanges,  fe.  Femur, 
ro.  Patella,  ti.  Tibia,  ta.  Tarsus,  m,  t.  Metatarsus,  cl.  Clavicle. 


Fig.  96. 


Skeleton  of  Bat.  The  descriptive  letters  are  the  same  as  in  Fig.  95. 


twenty -three.  The  Lumbar  arc  usually  the  largest  in  size, 
and  their  range  is  from  two  to  nine.  The  Sacral  consist 


AND  PHYSIOLOGY. 


87 


usually  of  four,  but  vary  from  one  to  nine,  and  as  in  man, 
are  almost  always  consolidated.  The  Caudal  vary  exceed- 
ingly in  number,  sometimes  amounting  to  forty-six.  When 
of  this  number,  they  gradually  dwindle  away  towards  the  ex- 
tremity of  the  tail,  and  lose  the  characteristics  of  vertebrae, 
and  become  mere  ossicles  or  bits  of  bone. 

193.  On  what  length  of  Neck  depends. — Hence  we  see 
that  the  length  of  the  neck  in  quadrupeds  does  not  depend 
on  the  number,  but  on  the  length  of  vertebrae,  since  the  Cam- 
eleopard  (Fig.  97), 


Skeleton  of  Cameleopard.  C.  Cervical  Vertebree.  D.  Dorsal  Vertebra}.  L.  Lumbar 
Vertebrae.  S.  Sacral  Vertebrae,  cd.  Caudal  Vertebrae.  51.  Scapula.  53.  Humerus. 
54.  Ulna.  55.  Eadius.  56.  Carpal  Bones.  57.  Metacarpus,  iii.  and  iv.  Phalanges.  62.  Inno- 
minatum.  64  and  65.  Femur.  66'.  Patella.  66.  Tibia.  67  and  68.  Tarsus.  69.  Metatarsus, 


88 


HITCHCOCK’S  ANATOMY 


which  has  the  longest  neck,  has  only  seven  cervical  vertebrjB, 
the  same  number  with  the  Mole  (Fig.  98),  an  animal  with 


Fig.  98. 


Skeleton  of  the  Mole.  The  illustrative  Figures  represent  the  same  as  in  Fig.  97. 


one  of  the  shortest  necks  among  quadrupeds.  Cuvier  states 
that  in  general  the  length  of  the  neck  is  such,  that,  added  to 
the  head,  the  length  of  both  is  equal  to  the  height  of  the  ani- 
mars  shoulders  above  the  ground.  If  this  were  not  the  case, 
grazing  animals  could  not  reach  their  food,  nor  any  quadru- 
peds their  drink  without  bending  the  legs. 

194.  Shape  of  Body. — The  shape  of  the  body  of  quadru- 
peds, whether  slender,  or  short  and  thick,  depends  on  the 
number  and  size  of  the  Lumbar  and  Dorsal  vertebrae. 

195.  Bones  of  Skull.  Elephant’s  Head,  Styloid,  and 
Tympanic  Bones. — The  general  arrangement  of  the  bones 
of  the  skull,  as  well  as  their  number,  corresponds  very  nearly 
with  those  of  man.  The  two  Parietals  are  usually  small 
bones,  and  sometimes  united  into  one.  This  is  true  of  the 
Horse  and  the  Bats.  In  the  Hog  and  Rhinoceros  the  two 
parietal  bones  are  united  in  one,  while  their  frontal  bone  is 


What  peculiarity  about  Lum])ar?  What  of  the  Sacral?  TIow  large  a number  of  Sa- 
cral are  sometimes  found?  19-b  Upon  what  does  the  length  of  neck  in  quadrupeds  de- 
pend on  ? Instance  the  OirafFe  and  Mole.  What  is  the  general  rule  about  the  length  of 
'the  neck?  194.  What  does  the  shape  of  the  body  mainly  dcj)cnd  on?  195.  How  do 
the  Parietals  sometimes  differ  from  man? 


AND  PHYSIOLOGY. 


89 


Fia.  99. 


Skull  of  Horse,  oc.,  f.  Occipital,  Temporal,  and  Frontal  Bones,  n.,  m.,  im. 
and  mi.^  Nasal,  Superior  Maxillary,  Intermaxillary,  and  Mandibular  Bones,  o.  Orbit. 
i.  Incisive  Teeth,  ono.  Molar  Teeth. 


in  two  pieces.  In  nearly  all  the  orders  of  mammalia  this 
hone  (the  frontal)  is  always  found  in  two  pieces.  In  the 
Elephant  the  bones  of  the  cranium  are  all  united  into  one 
at  an  early  period  in  life,  forming  but  one  piece,  in  order 
probably  to  make  it  sufficiently  strong  to  support  the  great 
weight  which  is  brought  upon  these  bones  by  the  tusks 
and  proboscis.  The  Styloid  process  of  the  temporal  bone 
is  usually  in  mammals  a separate  ossicle.  The  bone  which 
contains  the  organ  of  hearing  in  all  mammals,  except 
man  and  the  Apes,  is  a separate  bone  called  the  Tympanic, 
and  is  not  simply  the  petrous  portion  of  the  temporal  as  in 
man. 

196.  Bones  of  Face,  lutermaxiliaries,  Lower  Jaw. — 
In  the  Face  too  the  bones  correspond  very  nearly  with  those 
in  man.  The  essential  difference  is  found  in  the  upper  jaw. 
Instead  of  the  two  superior  maxillaries  meeting  each  other  on 
the  median  line  of  the  body  in  front,  there  are  two  other  bones 
between  them  called  the  Intermaxillaries.  These  are  very 
conspicuous  in  animals  provided  with  large  canine  teeth,  or 
tusks,  as  the  Elephant  and  Squirrel.  The  Lower  Jaw  in 


What  peculiarity  about  the  bones  of  the  Elephant’s  skull?  What  bone  is  wanting  in 
the  Whale?  Describe  the  Tympanic  Bone.  196.  In  what  respect  do  the  bones  of  the 
face  in  Mammals  differ  from  those  in  man  ? Where  are  the  Intermaxillaries  ? 


90 


II  I T CMI  C O C K ’ S A X A T O M Y 


quadrupeds  generally  consists  of  two  pieces,  tlie  division  being 
made  on  the  median  lino  of  the  body.  In  the  Hog,  Horse 
and  Cow  it  consists  of  a single  bone.  In  the  Greenland 
Whale  it  is  in  its  simplest  form,  which  is  that  of  two  arched 
ribs. 

197.  Form  of  Skull,  of  Oraiig  Oiilangs. — Viewed  as  a 
whole  the  form  of  the  skull  departs  most  from  that  of  man  in 
the  lowest  orders.  In  the  Ornithorynchus  the  face  is  pro- 
longed into  a beak  or  bill,  and  in  the  Horse  the  facial  por- 
tion of  the  head  is  four  times  larger  than  the  cranial,  exactly 
the  reverse  of  the  case  in  man.  In  the  young  Orang  Outangs 
the  form  of  the  skull  very  closely  resembles  that  of  man,  and 
in  the  adult  the  size  of  the  exterior  of  the  cranium  nearly 
equals  that  of  man,  though  its  capacity  is  considerably  le^s. 

198.  Teeth  of  (liiadrupeds,  Carnivorous,  Herbivorous, 
Insectivorous  and  Barbed  Teeth. — The  Teeth  of  Mammals 
vary  exceedingly.  They  may,  however,  be  classed  under  the  two 
divisions  of  flesh  and  vegetable  eating,  according  to  the  food 
of  the  animal.  Those  made  to  live  on  meat  are  sharp  and 

pointed,  for  simply  tearing  the  flesh 
Fig.  100.  into  such  small  portions  that  it 

can  be  swallowed,  while  those  eat- 
ing herbs  and  grass,  have  the  front 
teeth  with  sharp  edges  like  that 
of  a knife  for  cropping  the  food, 
and  back  teeth  with  flat  surfaces, 
or  vertical  ridges  of  enamel  in- 
terspersed between  the  ivory  or 
dentine,  which  act  the  same 
part  when  brought  together  with 

Teeth  of  a Lion  (Carnivorous  Animal  ) lateral  motioil,  aS  do  the  Upper 


"VVliat  of  tlie  Lower  Jaw?  197.  In  what  orders  does  the  head  differ  most  from  that  of 
man?  llow  docs  the  skull  of  the  Orang  Oiitang  differ  from  that  of  man  ? 19S.  What 
are  the  two  kinds  of  teeth  among  mammals?  Describe  each.  Give  the  reason  why  the 
teeth  arc  furnished  as  they  arc. 


AND  PHYSIOLOGY. 


91 


and  nether  millstone  for  grinding  grain.  Those  which  live 
upon  small  insects  have  conical  teeth  wdth  corresponding  de- 
pressions in  the  opposite  jaw  in  order  to  crush  the  skeletons 
and  envelops  of  their  prey.  The  Seals,  which  live  on  Fish, 
are  provided  with  barblike  appendages  similar  to  those  on  fish- 
hooks, in  order  that  they  may  hold  their  slippery  prey. 

199.  Humerus,  in  Burrowing  Animals. — The  Humerus 
is  generally  a long  cylindrical  tube,  with  a large  rounded 
head  at  its  upper  extremity.  But  in  swimming  and  burrow- 
ing animals  it  is  a short  and  curved  bone,  with  each  extrem- 
ity very  much  modified  for  the  attachment  of  muscles,  since 
the  fore-legs  of  such  animals  need  to  be  used  with  great  fre- 
quency and  force. 


200.  Bones  of  Fore-Arm.  Carpus,  Metacarpus,  Pha- 
langes.— The  element  in  which  mammals  live,  greatly  modi- 
fies the  bones  of  the  fore-arm  and  hand.  (Fig.  103,  p.  92.) 
In  general  there  are  two  bones  in  the  fore-arm,  and  but  few 
animals  have  the  power  to  move  these  one  upon  another  like 
man.  The  Carpus  is  constantly  made  up  of  two  rows,  though 
not  of  the  same  number.  They  vary  from  five  to  eleven.  The 
Metacarpus  consists  of  five  elongated  bones  for  the  most  part. 
But  these  are  three  in  the  Rhinoceros,  and  one  with  tw^o 

What  is  remarkable  about  the  teeth  of  the  Seal?  199.  What  is  the  general  outline  of 
the  llninerus?  In  what  animals  is  it  modifie<l  ? 200.  What  effect  has  the  element,  in. 
which  animals  live,  upon  tlie  anterior  extremities  ? How  do  the  Carpal  Bones  range  in 
number?  What  arc  the  exceptions  to  the  typical  number  five  of  the  Metacarpus ? 


92 


HITCHCOCK’S  ANATOMY 


Fig.  103. 

A B C D E F 


Anterior  Members  of  different  Animals.  A.  Fish.  B.  Bird.  C.  Dolphin.  B.  Deer. 
E,  Bat.  F.  Man. 

rudimentary  bones  in  the  Horse.  From  one  to  five  fingers  are 
usually  found,  of  which  the  thumb  is  generally  rudimentary, 


Fig.  104.  Fig.  105. 


TTind  Foot  of  Horse,  t.  Tibia,  ta.  and  Foot  of  Stag.  (Bepresentative  let- 

fa'.  Tarsus,  c.  Metatarsus  or  Canon  Bono.  ters  the  same  as  in  the  last  figure.) 
8.  Rudimentary  Bono.  /?.,  pi.,  and  pf., 
first,  second  and  third  Phalangea. 


AND  PHYSIOLOGY. 


03 


consisting  only  of  a single  bone.  The  Elephant  has  five  toes, 
the  Hog  four,  the  Rhinoceros  three,  the  Cow  two,  and  the 
Horse  one.  Sometimes  the  longest  finger  (paddle)  of  the 
Whale  contains  eleven  bones.  In  burrowing  and  swimming 
animals  the  fore-feet  are  generally  the  largest,  and  among  some 
quadrupeds  the  reverse  is  the  case.  The  posterior  extremities 
of  quadrupeds  are  usually  less  modified  than  the  anterior  ones, 
as  they  are  used  mainly  for  support  and  progression. 


OSTEOLOGY  OF  BIRDS. 

201.  Vertebrse,  Cervical,  Dorsal,  Caudal.— Birds  exhibit 
several  peculiarities  in  their  Spinal  Column.  The  number 
of  Cervical  Vertebrae  is  much  greater  than  in  mammals, 
giving  them  long  and  flexible  necks.  (Eig.  106,  p.  94.) 
The  number  is  between  ten  and  fifteen,  but  the  white  Swan 
has  twenty-three.  The  Dorsal  Vertebrae  vary  in  number 
from  seven  to  nine,  and  admit  of  but  little  motion  upon 
each  other,  many  of  them  being  frequently  anchylosed  to- 
gether, as  in  the  human  sacrum.  (Fig.  107,  p.  95.)  The 
design  of  this  is  to  give  the  firmest  point  of  attachment  to 
wings  that  can  be  secured.  The  Caudal  Vertebrae  are  hol- 
low and  form  a complete  canal  for  the  spinal  marrow.  The 
last  one  has  a large  disc-shaped  process  upon  it  for  the  sup- 
port of  the  long  feathers  of  the  tail, 

202.  Bones  of  Head,  Os  ftuadratum.  Jugal  Bone. — 
The  bones  of  the  head  correspond  in  number  and  position 
for  the  most  part  wdth  those  of  the  mammalia.  (Fig.  108, 
p.  95. ) They  are,  however,  united  together  at  a very  early 
period,  and  the  sutures  can  not  be  recognized  except  in  very 
young  subjects.  One  point  of  difierence  between  these  skulls 

What  are  some  modifications  of  Phalanges?  201.  Compare  the  Cervical  Vertebrse  of 
Mammals  with  those  of  Birds.  What  number  of  Cervical  Vertebraj  has  the  Swan?  Why 
are  the  Dorsal  Vertebra?  usually  firmly  fixed  together  ? What  peculiarity  of  the  Caudal 
Vertebra?  ? 202.  What  can  be  said  of  the  Sutures  in  the  head  of  birds  ? 


04  HITCHCOCK’S  ANATOMY 

FlO.  106. 


'IV 

Skeleton  of  Swan.  C.  C.  Cervical  Vortebrje.  7).  7).  Dorsal  Yertebrao.  S.  S.  Sacral 
Vcrtcbrjc.  cft  Caudal  Vertebrae  bl.  Scapula.  52.  Coracoid  Bone.  53.  Humerus.  54 
and  55.  Radius  and  Ulna.  5C.  Carpus.  57.  Metacarpus.  58.  Furcula.  62.  Innominata. 
€3.  Sacrum.  64.  I’ubis.  65.  J-’emur.  66.  Tibia.  60'.  Patella.  67.  Fibula.  09.  Tarso 
Metatarsus,  i.,  ii.,  iii.t  iv.  Plialangcs. 


AND  PHYSIOLOGY. 


95 


Fig,  107, 


Coccyx. 


Tibia. 


Tarsus. 


Skeleton  of  the  Goeland. 

and  those  of  the  mammals  is  that  the  occipital  bone  con- 
sists of  four  parts  instead  of  one.  A small  bone,  too,  is  al- 
ways present  called  the  Os  Quadratum,  in  close  proximity 
with  the  occipital,  temporal,  and  maxillary  bones.  A Jugal 


Fig.  108. 

Orbit.*  Inter-Oibitar  Septum. 


Head  of  the  Eagle. 


What  bone  in  the  skull  of  birds  that  demands  attention? 

5 


96 


II I T c Ti  c o r;  K ’ s anatomy 


Bone  is  also  found  which  is  similar  in  position  to  the  zygo- 
matic process  of  the  temporal  bone  in  man. 

203.  Bill. — Teeth  are  entirely  wanting  in  Birds,  their 
place  being  supplied  by  a single  horny  projection  on  each  jaw 
known  as  the  Bill.  Teeth  are  not  needed  by  these  animals, 
since  mastication,  where  it  is  necessary  that  it  should  be  per- 
formed, is  done  by  the  gizzard. 

204.  Ribs. — The  Bibs  are  very  firmly  articulated  with  the 
sternum  by  bone  and  not  cartilage,  so  that  they  have  a ten- 
dency to  keep  the  thorax  as  fully  distended  as  possible  all 
the  time,  which  is  its  natural  position. 

205.  Sternum,  in  wlinl 
Birds  largest. — The  Ster- 
num is  the  most  striking  of 
all  the  bones  in  a bird.  It 
is  the  largest  bone  in  their 
bodies,  a flattened  and  some- 
times quadrangular  bone,  hav- 
ing upon  its  anterior  surface 
a prominent  ridge  like  the 
keel  of  a ship,  for  the  attach- 
ment of  the  pectoral  muscles 
used  in  flight.  The  size  of 
this  ridge  generally  stands  in 
direct  relation  to  the  powers 
of  rapid  flight,  and  hence  in 
the  Humming  Bird,  one  of  the  swiftest  on  the  wing,  it  is 
proportionally  the  largest. 

206.  Clavicles,  Coracoid  Bone. — The  Clavicles  of  birds 
present  a marked  peculiarity.  They  both  unite  at  their  an- 
terior extremity,  forming  a forked  bone  known  as  the  Fur- 

203.  What  servos  the  ])urposo  of  teeth  for  Birds?  204.  llow  does  the  articulation  of 
the  ribs  affect  tlio  condition  of  the  chest?  205.  Which  i.s  tlie  largest  bone  in  birds? 
How  may  wo  know  the  powers  of  flight  in  a bird  by  the  keel  of  the  Sternum  ? 206.  What 
do  the  clavicles  of  birds  form  as  they  are  united  together? 


Fig.  100. 


o 


Bones  of  Sternum  and  Shoulder  of 
Birds,  s.  The  Sternum,  e.  Notch  of  the. 
Bternum.  co.  Origin  of  the  Sternal  Kibs. 
b.  Crest,  f.  Fourchette.  c.  Coracoid  Cla- 
vicle. 0.  Scapula. 


AND  PHYSIOLOGY. 


97 


cula,  merry  thought^  or  wish  bone.  They  also  possess  another 
bone  which  acts  the  part  of  a clavicle,  called  the  Coracoid. 
It  reaches  from  the  scapula  to  the  sternum,  side  by  side  with 
the  Furcula,  and  is  a principal  source  of  support  to  the 
wings  in  flight.  There  is  a bone  analogous  to  this  among 
some  reptiles. 

207.  Humerus. — The  Humerus  is  generally  a larger  and 
stouter  bone  than  the  femur,  contrary  to  the  relative  propor- 
tion in  man.  This  is  because  the  anterior  extremities  of  birds 
are  of  much  more  importance  in  their  habits  than  the  poste- 
rior ones,  since  the  hind  legs  in  most  of  the  flying  birds  act 
merely  as  a support  for  the  body  when  at  rest,  and  are  not  of 
special  service  for  running  or  scratching. 

208.  Bones  of  Wings,  Fingers. — The  two  bones  of  the 
fore-arm  are  proportionally  longer  than  the  same  bones  in 
mammals,  and  are  longest  in  birds  of  flight.  The  carpus  is 
represented  by  two  short  bones,  and  the  metacarpus  is  of  the 
same  number.  In  some  birds  the  thumb  is  entirely  wanting, 
but  when  present  it  is  made  up  of  two  bones.  The  little 
finger  has  only  one  bone.  The  middle  finger  is  the  longest, 
consisting  of  two  and  even  three  bones.  ^ 

209.  Femur,  Tarso-Metatarsus. — The  Femur  is  both 
thicker  and  shorter  than  the  bones  below  it,  which  constitute 
the  leg.  The  Fibula  is  always,  partially  at  least,  united  with 
the  tibia  at  its  lower  extremity.  The  Tarsal  and  Metatarsal 
Bones  are  found  as  one,  called  the  Tarso-Metatarsus,  which 
has  at  its  lower  extremity  three  pully-shaped  heads  for  the 
attachment  of  the  toes. 

210.  Sesamoid  Bones. — Sesamoid  Bones  are  abundant  in 
birds,  and  in  many  cases  even  the  tendons  themselves  become 

Is  this  peculiar  to  birds  alone  ? 207.  What  is  the  comparative  length  and  size  of  the 
Humerus  and  Femur  in  birds  ? Why  are  the  anterior  extremities  in  most  cases  the 
longest?  20S.  What  is  said  of  the  two  bones  of  the  fore-arm?  How  many  bones  are 
there  in  the  Carpus?  Describe  the  fingers  of  birds.  209.  What  peculiarities  in  the 
lower  extremities  of  birds?  Describe  the  Tarso  Metatarsal  Bone.  210.  What  is  «aid 
about  Sesamoid  Bones  in  birds  ? 


08 


HITCHCOCK’S  ANATOMY 


considerably  ossified.  This  is  especially  true  of  those  in 
the  leg. 

211.  Birds  Bones  arc  liollow. — The  bones  of  birds  are 
more  or  less  hollow  internally,  devoid  of  marrow,  and  per- 
meated by  air.  Hence  they  are  provided  with  openings  con- 
nected with  the  respiratory  apparatus  through  which  the  air  is 
brought  into  them.  As  a general  rnlc  the  capacitj’’  and  extent 
of  these  openings  throughout  the  skeleton  depends  on  the  size 
of  the  bird,  and  its  powers  of  flight,  since  small  though  rap- 
idly flying  birds  have  few  hollow  bones ; in  larger  and  higher 
flying  species,  however,  they  are  numerous.  In  the  Apteryx 
of  New  Zealand  there  is  the  greatest  want  of  these  cells.  This 
bird  has  no  wings,  but  can  run  and  even  burrow  in  the  earth 
very  rapidly.  Those  bones  which  convey  the  air,  difier  from 
all  others  in  appearance  by  their  whiteness  and  more  com- 
pactly cancellated  or  cellular  structure. 

OSTEOLOGY  OF  REPTILES. 

212.  Number  of  Vertebrfe  in  Reptiles. — The  Vertebrae 
of  Reptiles  vary  exceedingly  in  number.  For  whilst  in 
the  tailless  Batrachia  only  nine  or  eight  cervical  vertebrae  are 
counted,  some  serpents  have  full  300.’’  Those  of  Batrach- 
ians  have  long  transverse  processes. 

213.  Ribs;  Use  of  Ribs  to  Serpents. — “ In  the  serpents 
the  ribs  are  both  very  numerous  and  very  movable ; w here 
they  cease  the  tail  begins ; here  the  Caudal  vertebrae  may  be 
distinguished  from  the  other  vertebrae  of  the  trunk,  whilst  all 
distinction  of  dorsal  and  lumbar  vertebrae  fails.”  They  are 


211.  Why  are  birds’  bones  usually  holloAV  and  more  or  less  occupied  by  cavities? 
212.  What  is  the  number  of  vertebrro  in  Reptiles?  213.  Give  the  number  of  ribs  in 
Reptiles.  How  do  they  differ  from  those  of  quadrbpeds  ? Of  what  service  are  they  to 
the  animal  ? 


AND  PHYSIOLOGY. 


99 


valuable  instruments  of  progression,  since  in  many  they  can 
be  placed  upon  the  ground  and  used  as  feet. 

214.  Shell  of  Tortoise. — In  the  Tortoise  that  portion 
which  is  commonly  called  the  shell,  is  made  up  of  the  Cara- 


Fig.  110. 


p f 


Skeleton  of  the  Tortoise;  the  Plastron  has  been  removed,  vg.  Cervical  YertebrjE^ 
vd.  Dorsal  Vertebrae,  c.  Ribs.  cs.  Sternal  Ribs. — The  Marginal  Bones  of  the  Cara-, 
pace:  o.  Scapula,  cl.  Collar  Bone.  co.  Coracoid  Bone.  5,  Pelvis,  f.  The  Femur, 
t.  Tibia,  p.  Fibula. 

pace  or  upper  portion,  and  the  Plastron,  or  lower  one.  The 
Carapace  seems  to  be  a mere  expansion  of  the  vertebrae,  and 
the  Plastron  -an  expanded  sternum.  Hence,  as  the  annexed 


214.  What  is  the  Carapace  and  what  is  the  Plastron  in  the  Turtle  family?  From  what 
bones  are  they  developed  ? 


100 


HITCHCOCK’S  ANATOMY 


cut  shows,  the  skeleton  of  the  Tortoise  is  a very  simple  one, 
and  the  skeleton  of  the  Frog,  as  shown  in  Fig.  Ill,  is 
equally  simple. 

215.  Humerus. — The  Humerus  of  the  Tortoise  is  short 
and  very  much  curved.  This  is  made  so  in  order  that  the 
animal  may  thrust  its  extremities  out  of  the  shell  and  reach 
the  ground,  which  could  not  be  done  if  the  humerus  were 
straight  as  it  is  in  most  of  the  other  vertebrate  animals. 

216.  Femur. — The  Femur  is  curved  in  the  same  animals 
for  the  same  reason. 

217.  Phalanges. — Frogs  generally  have  four  fingers,  with 
from  two  to  four  phalanges  in  each  finger.  Tortoises  and 
Lizards  generally  have  five  fingers,  and  from  two  to  five 
phalanges  in  each  finger. 


Fig.  111. 


Skeleton  of  tke  Frog. 


OSTEOLOGY  OF  FISHES. 

218.  Bony  and  Cartilaginous  Fishes.— The  skeletons  of 
Fishes  are  of  two  kinds,  those  made  up  of  bony,  and  those  of 
cartilaginous  matter.  (Fig.  112.)  The  microscopic  structure 
of  the  scale  of  a Pike  is  seen  in  Fig.  113.  Of  the  former  kind 


215,  Why  is  tho  lluinenis  of  tlio  Tortoise  curved?  2ir.  How  many  fingers  have 
Frogs,  Lizards,  and  Tortoises?  218.  AVhat  are  tho  two  kinds  of  skeletons  in  Fishes? 
Give  examples  of  each. 


AND  PHYSIOLOGY. 


101 


as  representatives  are  the 
Shad  and  Tlounder,  and  of 
the  latter,  the  Shark  and 
Sturgeon. 

219.  Two  Kinds  of  Ver- 
tebra;.— The  only  kinds  of 
Vertebra©  in  Fishes  are  the 
Dorsal  and  Caudal.  These 
vary  in  number  from  seven- 
teen to  more  than  a hundred. 
Their  bodies  (vertebrae)  pre- 
sent on  both  articulating  sur- 
faces a conical  depression  which 
is  filled  wdth  a soft  matter 
having  the  same  use  as  the 
elastic  intervertebral  sub- 
stance in  the  human  vertebral 
column. 

220.  No  Sternum  or  Pel- 
vis.— The  Sternum  and  Pel- 
vis are  both  wanting  in  fishes, 
and  the  anterior  and  posterior 
extremities  are  rudimentary, 
being  represented  by  fins. 


Pig.  112. 


Skeleton  of  the  Perch, 


Fig.  113. 


Section  of  the  bony  scale  of  Tepidoateus.  a.  Showing  the  re^nlar  dir^tribution  of  the 
Lacunae  and  of  the  connectinaj  Canalicnll.  t.  Small  portion  more  higrlily  magnified. 


219.  What  are  the  only  Vertebr.'c  of  Fishes?  What  is  peculiar  about  their  articula- 
ting surfaces  ? 220.  Why  have  Fishes  no  Sternum  or  Pelvis  ? 


102 


IIITCnCOCK’S  ANATOLIY 


221.  Head, — The  bones  of  the  Head  in  this  class  of  ani- 
mals are  numerous  and  exceedingly  complicated,  being  in 
fact  a difficult  portion  of  study  in  comparative  osteology.  It 
is,  however,  a subject  of  great  interest  to  a thorough  scholar 
of  this  branch  of  anatomy  ; but  as  so  little  of  it  can  bo  gen- 
eralized, it  must  be  omitted  h re  altogether. 

222.  Great  Variety  of  Tcctli. — The  Teeth  present  every 
possible  variety  in  position  and  size,  and,  as  Sir  Richard 
Owen  says,  ‘‘they  average  in  number  from  zero  to  count- 


Fig.  114. 


jio 

Head  of  the  Pike.  c.  Cranium,  n.  Nasal  Fossjb.  im.  Intermaxillary  Bone. 
m.  Upper  Jaw.  op.,  io.  Bones  peculiar  to  the  head  of  fishes. 


less  quantities.’^  Some  teeth,  in  shape  and  location  re- 
semble the  pavement  of  the  street,  others  are  of  a delicate 
hook-shape,  and  others  still  are  fine  as  hairs,  and  are  located 

Fig.  115. 


ITcad  of  a Shark. 


221.  What  is  remarkable  with  respect  to  the  hones  of  the  Head  in  this  class?  222.  Whal 
is  said  about  tho  variety  of  Fishes’  Tooth  ? How  numerous  are  they  found  at  times? 


AND  PHYSIOLOGY. 


103 


on  the  jaws,  tongue,  and  palate.  They  are  repeatedly  re- 
newed during  the  life  of  the  animal.  Fig.  116  represents 
the  microscopic  structure  of  the  tooth  of  an  Eagle  Ray. 


Tig.  116. 


Microscopic  structure  of  Tooth  of  Eagle  Eay. 


223.  Skeleton,  or  Harder  Parts  of  Invertebrata.—The 
harder  parts  of  invertebrate  animals  generally  differ  so  much 
from  bones  in  composition  and  structure  that  the  term  Osteo- 
logy may  perhaps  be  less  proper  than  that  of  Skeleton  in 
describing  them. 

224.  Skeletons  of  Cr  ust  ace  an  s— Among  the  Articu- 
lata  the  Crustaceans  have  a more  or  less  solid  external  crust 
of  carbonate  of  lime  in  a base  of  peculiar  azotic  matter,  in- 
soluble in  caustic  potash,  called  Chitine, 

225.  Skeletons  of  Insects . — Insects,  the  most  numerous 
class  of  articulated  animals,  have  a chitinous  covering,  gener- 
ally leathery,  but  sometimes  solid.  The  Arachnoidea  have  a 
similar  skin,  soft  or  coriaceous,  rarely  horny ; and  the  Anne- 
lida a very  thin  epidermis.  The  Helminthes,  Rotatoria,  and 
Turbellaria,  reckoned  in  this  branch  of  the  animal  kingdom 


What  is  curious  about  their  renewal?  224.  Describe  the  skeleton  of  Crustaceans? 
325.  What  is  the  skeleton  of  Insects  ? 


5^ 


104 


HITCHCOCK’S  ANATOMY. 


by  some  eminent  writers,  have  a skin  more  or  less  hard,  and 
sometimes  spinous. 

Fig.  117. 


Microscopic  structure  of  the  Spine  of  Sea  Iledge-llog. 

226.  Skeleton  of  the  Mollusca.  — In  all  the  three 
great  classes  of  Molluscs,  the  Acephala,  the  Cephalophora, 
and  the  Cephalopoda,  the  animal  possesses  a mantle  by  which 
it  is  able  to  secrete  a solid  deposit,  mainly  composed  of  car- 
bonate of  lime,  which  it  spreads  over  nearly  all  the  body,  and 
is  fastened  to  it  by  muscles.  In  the  Acephala  this  skele- 
ton is  in  two  pieces,  called  valves ; in  the  Cephalophora,  it  is 
in  one  piece,  except  that  a calcareous  plate  is  attached  to  the 
foot  to  close  the  orifice.  The  organic  base  of  these  shells 
sometimes,  but  rarely,  predominates  over  the  calcareous  part. 
In  the  Cephalopoda  there  are  cartilages  for  the  attachment  of 
muscles  similar  to  the  same  substance  in  vertebrate  animals. 
In  the  Argonauta  and  Nautilina  of  this  class,  the  mantle 
secretes  an  external  shell ; but  in  the  Loligina,  or  Cuttle  Fish 
family,  it  is  internal. 

The  structure  of  the  shells  of  Molluscs  is  often  complicated 
and  beautiful. 

227.  Skeletons  of  llie  Radiata. — Among  the  Polypi 
some  are  entirely  Soft ; others  have  a solid  skeleton,  which 

22C.  Describe  the  skeleton  of  Molluscs.  227.  What  are  the  skeletons  of  Radiates  ? 
What  is  their  chemical  composition  ? 


AND  PHYSIOLOGY. 


105 


Fia.  118. 


Microscopic  view  of  Shell  of  Pinna. 


13  calcareous,  horny,  or  leathery.  This  skeleton,  called  a 
polypary,  or  in  popular  language  coral,  is  secreted  by  the 
skin  of  the  animal,  and  seems  to  be  truly  an  internal  skele- 
ton. It  contains,  say  ninety-five  per  cent,  of  carbonate  of 
lime,  some  two  or  three  per  cent,  of  fluorides  and  phosphates, 
and  from  four  to  eight  per  cent,  of  organic  matter. 

The  Acalephae,  another  class  of  Radiates,  are  mostly  gela- 
tinous ; but  a few  are  cartilaginous,  and  some  have  a nuclear 
skeleton.  The  Echinodermata,  with  few  exceptions,  have  an 


Fig.  119. 


Microscopic  section  of  hinge  of  Mya  showing  a crystalline  structure. 


What  is  coral  ? What  is  the  skeleton  of  other  Radiates  ? 


106 


HITCHCOCK’S  ANATOMY. 


external  skeleton  liiglil  / calcareous.  In  the  Asteroidea  there 
is  also  an  internal  articulated  skeleton  Tiie  structure  ot' 
these  skeletons  is  too  complicated  for  description  here.  Tlie 
Echinidae  are  remarkable  for  calcareous  knobs  and  rays,  both 
sharp  and  blunt,  sometimes  several  inches  long  ; hence  this 
common  name,  Sea  Iledge-Uog,  or  Porcupine. 

Skeletons  of  the  Protozoa. — The  organisms  brought 
together  by  Prof.  Owen  under  Protozoa,  are  the  Amorphozoa 
or  Sponges,  the  Foraminifera,  and  Infusoria,  which, he 
says,  ‘‘manifest  the  common  organic  characters,  but  without 
the  distinctive  super-additions  of  true  plants  or  animals.’"  Of 
the  skeletons  of  the  Infusoria  we  know  little,  save  that  they 
occur  fossil,  and  are  composed  of  silica  and  iron  ore. 

The  Foraminifera  are  small,  gelatinous  animals,  protected 
by  a calcareous  shell.  The  Sponges  are  said  to  be  ceratose 
or  horny ^ siUceons  or  flinty ^ and  calcareous  or  limy^  accord- 
ing as  their  frame- work  partakes  of  these  several  characters. 


What  is  said  of  the  skeletons  of  the  Protozoa?  What  of  the  Forminifera? 


CHAPTER  SECOND 


THE  MOVING  POWERS  OF  THE  SYSTEM.— MYOLOGY,  OR  THE 
HISTORY  OF  THE  MUSCLES. 


DEFINITIONS  AND  DESCRIPTIONS. 


228.  Microscopic  Structure  of  Muscle. — The  Muscles, 
known  as  flesh  or  lean  meat,  compose  a large  part  of  the 
extremities,  and  the  covering  of  the  trunk.  To  the  naked 
eye  they  appear  to  be  fibrous,  and,  with  the  assistance  of  the 
microscope,  these  fibers  are  found  to  be  bundles — called  Fasci- 
culi— of  still  smaller  fibers,  called  Ultimate  Fibers.  These 
seem  to  be  polygonal  in  form,  and  with  an  average  diameter 
of  4 ^oth  of  an  inch  in  man,  though  in  some  of  the  lower  ani- 
mals their  size  is  much  less. 


View  of  the  stages  of  development  of 
Muscular  Fiber.  1,  A Muscular  Fiber  of 
Animal  life  enclosed  in  its  Sheath  or 
Myolemma.  2,  An  Ultimate  Fibril  of  the 
same.  3,  A more  highly  magnified  View 
of  Fisr.  1,  showing  the  true  nature  of  the 
Longitudinal  Striae,  as  well  as  the  mode  of 
formation  of  the  Transverse  Striae.  The 
Myolemma  is  here  so  thin  as  to  permit  the 
Ultimate  Fibrils  to  be  seen  through  it.  4» 

A Muscular  Fibre  of  Organic  life  with  two 
ot  its  Nuclei ; taken  from  the  Urinary  Blad- 
der, and  magnified  600  Diameters.  5,  A 
Muscular  Fibre  of  Organic  life  from  the 
Stomach,  magnified  the  same. 

229.  Fibrils.  — The  ulti- 
mate fibers  are  still  further  divisible  into  what  are  termed 
Fibrils.  These  have  an  average  diameter  of  about  xoi^o  th 


228.  What  is  lean  meat?  IIow  does  muscle  appear  to  the  naked  eye?  What  are  the 
three  microscopio  elements?  Describe  each.  229.  What  is  the  diameter  ©f  the  Fibrils^ 


108 


HITCHCOCK’S  ANATOMY 


Fig.  121. 


A View  of  the  Frapnents  of  Striped  elementary  Fibers,  showing  a cleavafre  in  opposite 
directions — magnifle<l  300  Diameters.  1,  The  Longitudinal  Cleavage.  2,  The  Transverse 
Cleavage,  the  Longitudinal  Lines  being  scarcely  visible.  3,  Inc(>m[)lete  Fracture,  follow- 
ing tlie  opposite  surfaces  of  a Disc  which  stretches  across  the  Interval  and  retains  the  two 
Fragments  in  connexi  >n.  The  Edge  and  Surface  of  this  Disc  are  seen  to  be  minutely 
granular,  the  Granules  corresi)on(ling  in  size  to  the  thickness  of  the  Disc  and  to  the  dis- 
tance between  the  faint  Longitudinal  Lines.  4,  Another  Disc  nearly  detached.  5,  A de- 
tached Disc  more  highly  magnified,  showing  the  Sarcous  Elements.  6,  Fibrilhe  separated 
by  violence  from  each  other  at  the  broken  end  of  the  Fiber.  7,  8,  The  tw(»  appearances 
commonly  presented  by  the  separated  single  Fibrillae  ; more  highly  magnified,  at  7 the 
spaces  are  rectangular,  at  8 the  borders  are  scalloped  and  the  spaces  bead-like. 


of  an  inch,  and  number  about  650  in  each  ultimate  fiber. 
They  are  unprotected  hy  any  covering,  while  both  the  fasicu- 
■piQ,  122.  and  ultimate  fiber 

are  everywhere  pro- 
tected by  a delicate 
sheath  called  the 
Sarcolemma. 

230.  Organic,  or 
Unslripcd,  and  Ani- 
mal, or  Striped  Fi- 

Fibrils  of  Human  Muscle.  tcrS. All  the  mUS- 

cles  of  the  body  are  divided  into  two  classes,  according  to 
their  function.  Those  necessary  for  carrying  on  the  vital 
functions,  such  as  breathing  and  digestion,  are  called  Or- 
ganic, and  those  under  the  control  of  the  will  Animal  Fi- 
bers. In  addition  to  their  use  as  a means  of  distinction, 
they  may  be  known  by  their  appearance  under  the  micro- 

What  is  the  Sarcolemma ? On  what  clement  of  muscle  is  this  wanting?  230.  Give 
the  two  functional  classes  of  the  muscles. 


AND  PHYSIOLOGY. 


109 


Fm.  123. 


Transverse  Section  of  Human  Fibrillje 
showing  a Polygonal  form. 

scope,  the  Animal  Fiber  being 
marked  by  transverse  striiB, 
or  stripes  resembling  a beaded 
filament,  called  Striped  Fi- 
ber ; and  the  Organic  being 
made  up  merely  of  flattened 
bands  destitute  of  these  cross 
marks,  and  hence  called  Un- 
striped, or  smooth  fiber.  The 
unstriped  fibrils  are  developed 
from  cylindrical  or  spindle- 
shaped  nucleated  cells,  and 
are  surrounded  by  a peculiar 
fluid  known  as  muscle  j uice, 
which  is  unlike  the  plasma  of 
the  blood,  since  it  contains 
casein. 

231.  Tendons,  Aponeuro- 
ses,Bellyor  Swcllof  IheMus- 
c!e. — The  extremities  of  the 
muscles  are  composed  of  dense 
areolar  tissue  in  the  form  of 
tendons  or  cords,  and  that 
extremity  which  is  nearest  to 
the  center  of  motion  is  called 


Fig.  124. 


A broken  Muscular  Fiber  showing  tho 
sheath  or  myolemma  untorn. 

Fig.  125. 


ber.  a,  Two  cells  in  their  natural  state. 
hj  A cell  treated  to  acetic? acid,  showing  the 
nucleus  c. 

the  Origin,  while  the  one  most 


What  is  the  appearance  of  the  Animal  Fibre  under  tho  microscope?  Also  that  of  the 
Organic?  2S1.  State  the  composition  of  the  Tendons. 


no 


HITCHCOCK’S  ANATOMY 


remote  from  it  is  called  its  Insertion.  These  are  exceedingly 
firm  and  strong,  perfectly  inelastic,  and  can  not  be  torn  from 
the  bones  without  unnatural  violence.  If  the  extremity  of 
the  muscle  has  a large  surface  for  attachment,  its  tendon  is 
expanded  into  a broad  membranous  portion  termed  an  Apo- 
neurosis, as  may  be  seen  in  the  muscles  inclosing  the  abdo- 
men ; while  the  greater  portion  of  the  muscles  have  a fleshy 
portion  called  the  Swell  or  Belly,  and  the  tendinous  portion 
contracted  into  the  shape  of  a cord,  or  even  of  a thread.  In 
general  this  belly  of  the  muscle  is  in  a place  which  is  the 
most  firmly  fixed,  and  distant  from  the  point  to  be  moved,  in 
order  to  efiect  grace  of  motion,  and  beauty  of  form. 


Fig.  12G. 


A Eadiate  Muscle. 


232.  Forms  of  Muscles. — In  form  the  muscles  present  a 
great  diversity.  A Radiate  Muscle  (Fig.  126)  is  one  where 
the  fibres  radiate  from  a central  portion  to  distribute  them- 
selves upon  a large  surface.  In  the  Fusiform  (Fig.  127)  the 


Fig.  121. 


A Fusiform  Muscle. 


fibres  diminish  in  size  from  a center  to  each  extremity.  In 


What  is  the  fleshy  portion  of  the  muscle  called  ? What  is  an  Aponeurosis  ? Define  the 
Origin  and  Insertion  of  a muscle.  WHiere  is  the  Belly  of  the  musele  generally  located? 
233.  Describe  the  Ea<liatG  and  Fusiform  Muscles. 


AND  PHYSIOLOGY. 


Ill 


Fig.  128. 


A Doubly  Penniform  Muscle. 


the  Penniform  the  fibres  are  short  and  arranged  upon  a long 
tendinous  line,  like  the  plumes  upon  the  quill  of  a feather. 
The  circular  form,  called  Sphincter,  is  found  in  parts  of  the 
b )dy  where  the  fibres  are  circular,  surrounding  some  orifice 
which  they  partially  or  entirely  close  up  by  their  contraction. 
An  example  of  this  is  seen  around  the  eye  and  mouth.  A 
few  muscles  resemble  in  structure  a ribbon.  Others  a cord, 
and  others  are  very  thin  and  expanded,  so  that  they  resemble 
a membrane.  All  these  forms  are  thus  arranged  to  secure 
the  greatest  amount  of  power  with  dispatch,  and  also  the  most 
perfect  freedom  of  motion,  as  well  as  to  adapt  themselves  to 
the  amount  of  space  furnished  them  on  the  skeleton. 

233.  Number  of  Muscles,  Single  Muscles— The  number 
of  muscles  in  man  is  540,  being  more  than  twice  the  number 
of  the  bones.  They  are  nearly  all  arranged  in  pairs  ; that  is, 
both  sides  of  the  body  have  similar  muscles,  while  the  single 
or  unmated  muscles  are  only  thirteen.  Each  muscle  is  pro- 
vided with  one  or  more  antagonist  muscles,  or  those  which 
produce  motion  in  an  opposite  direction,  save  a very  few  sur- 
face muscles  about  the  head  and  neck,  where  the  elasticity  of 
the  integuments  produces  the  antagonistic  motion. 

234.  Fascia. — Every  muscle  is  covered  by  a firm  and 
slightly  elastic  membrane  called  Fascia,  which  serves  the 
double  purpose  of  keeping  the  fibres  firmly  in  their  place,  and 
also  of  producing  a tonic  pressure,  which  gives  increased 
strength  to  the  muscle.  An  illustration  of  the  utility  of  this 
pressure  is  seen  in  the  fact,  that  the  school-boy,  when  engaged 
in  running  as  rapidly  as  possible  in  his  sports,  ties  a handker- 

Describe  the  Penniform  and  Circular  Muscles.  Are  there  any  other  forms  of  muscles? 
Why  are  muscles  of  these  different  shapes  ? 203.  What  is  the  number  of  human  muscles  ? 
IIow  does  this  compare  with  the  number  of  the  bones?  How  many  unmated  muscles 
are  there?  What  is  meant  by  antagonist  muscles ? 234.  What  is  the  Fascia,  and  what 
purpose  does  it  serve  ? What  illustratioa  of  its  use  ? 


112 


II I T'C  II  C O C K ’ S 


A N A T O J^I  Y 


Pia.  129. 


Carpi  Itadialis  Longior.  19, 
Kxtensor  Ossis  Metacarpi 
Poilicis.  20,  Annular  Liga- 
ment. 21,  Palmar  Fascia. 
22,  Obliquiis  Extern  us  Ab- 
dominis. 23,  Linea  Alba.  24, 
Tefisur  Vagina3  Femoris.  25, 
Section  of  the  Spermatic 
Cord.  26,  Psoas  Magnus* 
27,  Adductor  Longue.  28, 
Sartorius.  29,  ^ Pectus  Fe- 
moris. 30,  Vastus  Exter- 
nus.  31,  Vastus  Internus. 
82,  Tendon  Patellie.  33,  Gas- 
trocnemius. 34,  Tibialis  An- 
tic us.  35,  Tibia.  36,  Ten- 
dons of  the  Extensor  Com- 
munis. 


Anterior  View  of  the  Muscles  of  the  Body. 

1,  Frontal  Bellies  of  the  Occiplto-Frontalis. 

2,  Orbicularis  Palpebrarum.  3,  Levator  Labii 
Superioris  Ala?que  Nasi.  4,  Zygomuticus  Mi- 
nor. 5,  Zygomuticus  Major.  6,  Massetcr.  7, 
Orbicularis  Oris.  8,  Depressor  Labii  Inferioris. 
9,  Platysrna-Myoides.  10,  Deltoid.  11,  Pecto- 
ralis  Major.  12,  Axillary  portion  of  the  Latis- 
simus  Dorsi.  18,  Serratus 
Major  Anticus.  14,  Biceps 
Flexor  Cubiti.  15,  Anterior 
Portion  of  the  Triceps  Ex- 
tensor Cubili.  16,  Supinator 
Padii  Longus.  17,  Pronator 
Eadii  Teres,  IS,  Extensor 


AND  PHYSIOLOGY 


113 


Fig,  130. 


cis.  19,  Extensor  Communis  DI- 
gitorum* Tendons.  20,  Olecranon 
and  Insertion  of  the  Triceps.  21, 
Extensor  Carpi  Ulnaris.  22,  Au- 
ricularis.  23,  Extensor  Commu- 
nis. 24,  Latissimus  Dorsi.  25,  Its 
Tendinous  Origin.  29,  Posterior 
Part  of  the  Obliquus  Externus. 
27,  Gluteus  Medius.  28,  Gluteus 
Magnus.  29,  Biceps  Flexor  Cru- 
ris. 30,  Semi-Tendinosus.  31, 
82,  Gastrocnemius.  33,  Tendo- 
Achilles. 


Posterior  View  of  the  Muscles  of  the 
Body.  1,  Temporalis.  2,  Occipital  por- 
tion of  the  Occipito-Frontalis.  3,  Corn- 
plexus.  4,  Spleniiis.  5,  Masseter.  C, 

Sterno-Cleido  Mastoideus.  7,  Trapezius. 

8,  Deltoid.  9,  Infra-Spinatus.  10,  Tri- 
ceps Extensor.  11,  Teres  Minor.  12,  Te- 
res Major.  13,  Tendinous  portion  of  the 
Tricei)S.  14,  Anterior  Edge 
of  the  Triceps.  15,  Supinator 

Eadii  Longus.  16,  Pronator 
Badii  Teres.  17,  Extensor 

Communis  Digitorum.  18,  Ex- 
tensor Ossis  Metacarpi  Polli- 

n 

W 


114 


HITCHCOCK’S  ANATOMY 


Fig.  131. 


A Transverse  Section  of  the  Neck,  show- 
ing the  Fascia  Profunda,  and  its  Pro- 
longations as  Sheaths  for  the  Muscles. 
1,  Platysma  Myoides.  2,  Trapezius.  3, 
Ligamentum  Nuchaj.  4,  Sheath  of  Sterno- 
Cleido-Mastoid.  5,  Muscle  itself.  6,  Point 
of  Union  of  its  Fascia.  7,  Point  of  Union 
of  the  Fascia  Profunda  Colli  of  each  side 
of  the  Neck.  8,  Section  of  the  Sterno- 
llyoid  Muscle.  9,  Section  of  the  Omo- 
Ilyoid  Muscle.  10,  Section  of  the  Sterno- 
Thyroid  Muscle,  11,  Lateral  Lobe  of  the 
Thyroid  Gland.  12.  Trachea.  13,  (Esoph- 
agus. 14,  Blood-vessels  and  Pneuinogas- 
tric  Nerve  in  their  Sheath.  15,  Longus 
Colli.  16,  Eectus  Anticus  Major.  17, 
Scalenus  Anticus.  18,  Scalenus  Medius 
and  Posticus.  19,  Splenius  Capitis.  20, 
Splenius  Colli.  21,  Levator  Scapula.  22, 
Complexus.  23,  Trachelo  - Mastoid.  24, 
Transversalis  Cervicis.  25,  Cervicalis  De- 
scendens.  26,  Seini-spinalis  Cervicis.  27, 
Multifidus  Spin®.  28,  A Cervical  Yertebra. 


chief  about  his  ivaist  in  order 
to  give  strength  to  liis  mus- 
cles. And  so  important  is 
this  membrane  to  the  muscu- 
lar system,  that,  upon  the 
thigh,  where  very  great 
strength  and  rapidity  of 
movement  is  required,  this 
membrane  is  thicker  than  in 
most  of  the  other  parts  of  the 
body  ; and  not  only  so,  but  a 
muscle  is  also  provided  for  the 
especial  purpose  of  rendering 
this  membrane  very  tense, 
when  any  violent  action  is 
required,  or  its  own  elasticity 
is  insufiBcient. 

235.  Descriptions  of  par- 
ticular Muscles. — In  such  a 
treatise  as  the  present  one,  it 
will  of  course  be  impossible 
to  describe  all  the  muscles  as 
minutely  as  the  bones  have 
been,  nor  will  it  be  necessary ; 
but  only  those  which  are  the 
most  interesting  and  instruc- 
tive. 


236.  Orbicularis  Palpebrsc. — The  muscle  which  surrounds 
the  eye  is  a sphincter  which  is  made  of  circular  fibres,  and 
when  contracted  closes  the  eye,  as  it  is  termed.  Consequently 
this  action  reituires  the  movement  of  no  bones,  and  no  attach- 
ment to  any  thing  but  the  soft  parts  of  the  face.  It  is  called 
the  Orbicularis  Palpebrfe.  Its  antagonist  is  the  Levator  Pal- 


What  is  Raid  about  tho  importance  of  this  fascia  upon  the  thigh  ? 236.  What  is  the  mus- 
cle that  opens  and  closes  tho  eye,  as  it  is  termed?  What  kind  of  a muscle  is  this? 
What  is  tho  antagonist  of  tho  Orbicularis  Palpebn®  ? 


AND  PHYSIOLOGY. 


115 


Fig.  132. 


A Front  View  of  the  Superficial  Layer  of  Muscles  on  the  Face  and  Neck.  1, 1,  Ante- 
rior Bellies  of  the  Occipito-Frontalis.  2,  Orbicularis  or  Sphincter  Palpebrarum.  8,  Na- 
sal Slip  of  Occipito-Frontalis.  4 Anterior  AuriculsB.  5,  Compressor  Naris.  6,  Levator 
Labii  Superioris  Aheque  Nasi.  7,  Levator  Anguli  Oris.  S,  Zygomaticus  Minor.  9, 
Zygomaticus  Major.  10,  Masseter.  11,  Depressor  Labii  Superioris  Alasque  Nasi.  12, 
Buccinator.  13,  Orbicularis  Oris.  14,  The  denuded  Surface  of  the  Inferior  Maxillary 
Bone.  15,  Depressor  Anguli  Oris.  16,  Depressor  Labii  Inferioris.  17,  The  portion  of 
the  Platysma  Myoides  that  passes  on  to  the  Mouth,  or  the  Musculus  Eisorius.  18,  Sterno- 
Ilyoideus.  19,  Platysma-Myoides.  It  is  wanting  on  the  other  side  of  the  Figure.  20, 
Superior  Belly  of  the  Orno-Hyoideus  near  its  insertion.  21,  Sterno-Cleido-Mastoideus. 
22,  Scalenus  Medius.  23,  Inferior  Belly  of  Omo-Hyoid.  24,  Cervical  Edge  of  the  Tra- 
pezius. 

pebrse,  -vvliich  takes  its  origin  far  back  on  the  sides  of  the 
cavity  of  the  orbit,  and  is  attached  to  the  upper  lid.  When 
contracted  it  opens  the  eye. 

237.  Orbicularis  Oris. — The  Orbicularis  Oris  (circular 
muscle  of  the  face)  by  its  contraction  closes  the  mouth.  Like 
the  corresponding  muscle  of  the  eye,  it  has  its  origin  and  in- 
sertion in  the  soft  parts  of  the  face,  and  is  made  up  of  concen- 


237.  'Where  is  the  Orbicularis  Oris,  and  what  is  its  use  ? 


116 


HITCHCOCK’S  ANATOMY 


trie  fibres.  And  tlic  antagonists  arc  those  muscles  wliicli  are 
inserted  into  it,  coming  from  the  different  bones  of  tlie  face 
moving  the  lips  and  nostrils,  and  giving  much  of  the  expres- 
sion of  emotion  in  the  countenance. 

238.  Hasseter  and  Temporal  Muscles, — The  elevators  of 
the  lower  jaAV  are  two : the  Masseter  (chewing)  and  the 
Temporal  (from  the  bone  on  which  it  lies).  They  are  at- 
tached to  the  posterior  portion  of  the  bone  near  the  joint,  since 
if  their  position  was  nearer  to  the  front  part  of  the  bone  they 
would  not  contract  sufficiently  to  bring  the  jaws  together. 

239.  Digastric  Muscle. — The  lower  jaw  is  carried  down- 
wards by  the  Digastricus  (tv/o  bellies)  muscle.  This  is  a long 
round  muscle  like  a cord,  which  commences  just  below  the 
lower  front  teeth,  and  from  thence  runs  downwards  and  back- 
wards to  the  os  hyoides,  where  it  runs  through  a tendinous 
loop  ; after  this  it  passes  upwards  and  backwards  to  the  mas- 
toid process  upon  the  temporal  bone,  just  behind  the  ear. 
The  contraction  of  this  muscle  then  will  open  the  mouth,  when 
the  os  hyoides  is  made  fast ; but  if  the  jaw  be  confined  by 
its  elevator  muscles,  the  os  hyoides  will  be  the  movable  por- 
tion, and  will  be  elevated.  The  necessity  of  such  an  arrange- 
ment is  evident  from  the  fiict,  that  no  muscle  from  the  jaw  to 
the  hyoides  would  be  of  sufficient  length  to  open  the  lower 
jaw  by  its  contraction;  and  if  it  vfere  to  run  backwards  to 
the  spinal  column,  the  violence  with  which  it  must  contract 
to  accomplish  its  object,  would  produce  such  pressure  upon  the 
vessels  and  nerves  of  the  neck  as  to  injure  them. 

^ 240.  Slcrno-Clcido-Mastoidous. — A bow,  or  bending  of 
the  head  upon  the  spinal  column,  is  effected  by  the  action  of 
the  Stcrno-Clcido-Mastoideus  muscle  (named  from  its  attach- 


Whrit  arc  its  antagonists  ? What  muscles  aid  very  much  in  giving  expression  to  tho 
countenance  ? 20S.  Wliat  are  tho  two  pairs  of  muscles  that  bring  the  jaws  together  in 
tho  act  of  clicwing?  231).  State  tho  muscle  that  opens  the  mouth.  What  mechanical 
peculiarities  in  its  structure  and  operation?  Why  tlio  necessity  of  such  a complicated 
arrangement?  240.  Wliat  is  tho  muscle  by  whoso  action  wo  bow  tho  head? 


AND  PHYSIOLOGY. 


in 


Fig.  133. 


A Lateral  View  of  the  Deep-seatefl  Layer  of  Muscles  on  the  Face  and  Neck.  1,  Tem- 
poral Muscle  deprived  of  its  Fascia.  2,  Corriisrator  Superdilii.  3,  Nasal  Slip  of  the  Oc- 
cipito  Frontalis.  4,  Superior  or  Nasal  Extremity  of  the  Levator  Labii  Superioris  Alsequo 
Nasi.  5,  Compressor  Naris.  G,  Levator  Anpruli  Oris.  7,  Depressor  Labii  Superioris 
Alreque  Nasi.  8,  Buccinator.  9,  Orbicularis  Oris.  10,  Depressor  Labii  Inferioris.  11, 
Levator  Labii  Inferioris.  12,  Anterior  Belly  of  the  Dicrastricus.  13,  Mylo-IIyoid.  14, 
Stylo-Hyoid.  15,  Thyro-IIyoid.  16,  Upper  Belly  of  the  Omo-TTyoid.  17,  Sterno-Cleido- 
Mastoid.  IS,  Stcrno-ITyoid.  19.  Scalenus  Anricus.  20,  Pectoralis  Major.  21,  Deltoid. 
22,  Trapezius.  23,  Scalenus  Medius.  24,  Levator  Scapulifi  and  Scalenus  Posticus.  25, 
Splenius.  23,  Complexus; 

ment  to  the  Sternum,  Clavicle,  the  Greek  for  which  is  kleis, 
and  the  mastoid  process).  The  form  of  this  muscle  is  essen- 
tially that  of  a thick  ribbon. 

241.  Muscles  of  the  Scapula.— The  Scapula  is  covered 
with  muscles  on  both  sides,  most  of  which  are  inserted  into 
the  head  of  the  humerus.  Their  use  is  to  rotate  the  hu- 

What  is  the  shape  of  this  muscle  ? 241.  What  actions  do  the  muscles  of  the  scapuU 
effect? 


118 


HITCHCOCK’S  ANATOMY 


Fig.  134. 


A View  of  the  Muscles  of  the  Back  as  shown  after  the  removal  of  the  Integuments.  1 
Occipital  Origin  of  the  Trapezius.  2,  Sterno-Cleido-Mastoideus.  8,  Middle  of  the  Tra- 
pezius. 4,  Insertion  of  the  Trapezius  into  the  Spine  of  the  Scapula.  5,  Dtdtoid.  6,  Sec- 
ond Head  of  the  Triceps  Extensor  Cubiti.  7,  Its  Superior  Portion.  8,  Scapular  portion 
of  the  Latissiinus  Dorsi.  9,  Axillary  Border  of  the  Pectoralis  Major.  10,  Axillary  Bor- 
der of  the  Pectoralis  Minor.  11,  Scrratus  Major  Anticus.  12,  Infra-Spinatus.  18,  Teres 
Minor.  14,  Teres  Major.  15,  Middle  of  the  Latissimus  Dorsi.  16,  External  Oblique  of 
the  Abdomen.  17,  Gluteus  Medius.  18,  Gluteus  Minimus.  19,  Gluteus  Magnus.  20, 
Fascia  Lumborurn. 

mcrus,  as  well  as  to  give  it  protection  where  it  articulates 
with  the  scapula,  and  to  keep  it  in  its  place. 


AND  PHYSIOLOGY* 


119 


242.  Biceps. — The  Biceps 
(two  heads,  or  points  of  at-, 
tachment)  is  the  muscle  which 
flexes  or  bends  the  arm  to- 
wards the  body.  It  arises 
from  the  head  of  the  humerus 
and  scapula,  and  is  inserted 
into  the  upper  end  of  the 
radius.  It  is  a very  fine  ex- 
ample of  a fusiform  muscle, 
and  though  acting  at  a great 
mechanical  disadvantage  as  to 
power,  it  effects  a rapid  move- 
ment. 

243.  Triceps. — The  Tri- 
ceps (three  heads),  its  antag- 
onist, is  similar  in  its  general 
form,  and  is  attached  to  the 
ulna  instead  of  the  radius. 
It  is  situated  upon  the  poste- 
rior side  of  the  humerus,  and 
the  force  with  Avhich  it  may 
be  made  to  contract,  is  seen 
in  the  pow'erful  blow  given 
by  the  boxer,  or  the  weights 
raised  by  extending  the  arms 
upon  the  instrument  made  for 
the  purpose  in  a gymnasium. 

244.  Muscles  of  the  Fore- 

Arm, — The  r ore- Arm  is  abun- 


Fia  135. 


A View  of  the  Muscles  on  the  Front  of 
the  Arm.  1,  Clavicle.  2,  Coracoid  Pro 
cess  and  Origin  of  the  Short  Head  of  the 
Biceps.  3,  Acromion  Scapul®.  4,  Head 
of  the  Os  Humeri.  5,  Tendon  of  the  Bi- 
ceps Muscle  in  the  Bicipital  Groove.  6, 
Ligamentum  Adscititium  dissected  off.  7, 
Cut  portion  of  the  Pectoralis  Major.  8» 
Long  Head  of  the  Biceps.  9,  Insertion  of 
the  Deltoid.  10,  Cut  portion  of  the  Ten- 


dinous Insertion  of  the  Pectoralis  Minor.  11,  Coraco-Brachialis.  12,  Short  Head  of 
the  Biceps.  13,  Latissimus  Dorsi.  14,  Inner  portion  of  the  Triceps.  15,  Body  of  the 
Biceps.  16,  Outer  portion  of  the  Triceps.  17,  Brachialis  Internus.  IS,  Origin  of  the 
Flexor  Muscles.  19,  Brachialis  Internus  near  its  Insertion.  20,  Tendon  of  the  Biceps. 
21,  Fasciculus  from  the  Biceps  Tendon  to  the  Fascia  Brachialis.  22,  Flexor  Carjn  Ea- 
dialis.  23,  Palmaris  Longus.  24,  Supinator  Eadii  Longus. 


242.  Why  is  the  name  Biceps  given  to  the  muscle  that  flexes  the  fore-arm  ? What 
mechanical  disadvantage  in  its  structure  ? What  gain  from  it?  243.  What  is  the  antag- 
onist*of  the  Biceps?  What  actions  show  its  mode  of  action  ? 

6 


120 


HITCHCOCK’S  ANATOMY 


Tig.  13G. 


A Yiew  of  tlie  Outer  Layer  of  the  Mus- 
cles on  the  Front  of  the  Fore-Arm  (Flex- 
ors). 1,  Lower  portion  of  the  Biceps 
Flexor  Cubiti.  2,  Brachialis  Internus.  3, 
Lower  Internal  portion  of  the  Triceps.  4, 
Pronator  Eadii  Teres.  5,  Flexor  Carpi 
Eadialis.  6,  Palmaris  Longus.  7,  Part  of 
the  Flexor  Sublirnis  Digitoruin.  8,  Flexor 
Carpi  Ulnaris.  9,  Palmar  Fascia.  10, 
Palmaris  Brevis  Muscle.  11,  Abductor 
Pollicis  Manus.  12,  Portion  of  the  Flexor 
Brevis  Pollicis  Manns.  The  Line  crosses 
the  Adductor  Pollicis.  13,  Supinator 
Longus.  14,  Extensor  Ossis  Mctacarpi 
Pollicis. 


dantlj  supplied  with  muscles, 
many  of  which  are  fusiform 
in  their  appearance,  and  all 
of  which  arc  for  the  purpose 
of  moving  the  hand  and  fin- 
gers. Most  of  the  fibres  run 
in  a direction  parallel  to  the 
bones  of  the  fore-arm,  but 
those  which  perform  the  ac- 
tions of  pronation  and  supina- 
tion lie  obliquely,  and  some 
nearly  at  right  angles  to  the 
long  muscles.  In  this  part 
of  the  body  the  muscles  are 
distinguished  by  slenderness 
of  form  and  consequent  deli- 
cateness of  tendon,  the  latter 
in  many  cases  being  equal  in 
length  to  the  muscular  fibre, 
since  there  are  very  few  mus- 
cles below  the  wrist,  and  those 
only  which  are  short  and 
thick,  for  the  purpose  of  mov- 
ing the  thumb  and  little 
finger. 

245.  Tendons  of  the  Fin- 
gers.— The  arrangement  of 
the  tendons  which  are  at- 
tached to  the  phalanges,  for 
the  motion  of  the  fingers, 
shows  the  contrivance  and 
skill  of  an  Infinite  Being.  In 


order  that  the  fingers  may  bo  slender  and  easily  moved,  it  is 
desirable  that  there  should  be  as  small  a quantity  of  matter  in 


244.  Give  the  goncrul  urningcmcrit  of  muscles  in  the  fore-arm.  How  do  the  Pronatora 
and  Supinators  lie? 


AND  PHYSIOLOGY, 


121 


Fia.  13t, 


Fig.  138, 


the  Hand.  1,  Annular  Ligament.  2,  2, 

Origin  and  Insertion  of  the  Abductor  Pol- 
licis.  3,  Opponens  Pollicis.  4,  5,  Two 
Bellies  of  the  Flexor  Brevis  Pollicis.  6, 

Adductor  Pollicis.  7,  7,  Lumbricales  aris- 
ing from  Tendons  of  the  Flexor  Profundus 
Digitorum.  8,  Shows  how  the  Tendon  of 
the  Flexor  Profundus  passes  through  the 
Flexor  Sublimis.  9,  Tendon  of  the  Flexor 
Longus  Pollicis.  10,  Abductor  Minimi 
Digiti.  11,  Flexor  Parvus  Minimi  Digiti. 

1-2,  Pisiform  Bone.  18,  First  Borsal  Inter-  ^ Under  Layer  of  Muscles 

osseous  Muscle.  Fore-Arm  (Flexors), 

1,  Internal  Lateral  Ligament  of  the  El- 
bow-Joint. 2,  Capsular  Ligament  of  the  Elbow-Joint.  8,  Coronary  Ligament  of  the 
Head  of  the  Radius.  4,  Flexor  Profundus  Digitorum  Perforans.  5,  Flexor  Longus 
Pollicis.  6,  Pronator  Quadratus.  7,  Adductor  Pollicis  Manus,  8,  Lumbricales,  9, 
Interossei. 


them  as  possible.  Hence,  as  above  stated,  the  muscle  that 
moves  them  is  situated  in  the  fore-arm,  and  the  tendon  is 
made  as  slender  as  possible.  But  here  another  arrangement 
claims  our  attention.  A set  of  four  tendons  from  a common 
muscle  is  attached  to  the  base  of  the  second  phalanx  of  each 
finger,  and  a second  set  to  the  third  row  of  phalanges.  The 
question  then  arises,  how  can  these  two  tendons  pass  upon 


245.  Desei’ibe  the  arrangement  of  the  tendons  of  the  fingers. 


122 


n I T c ir  c o c K M a k a t o ivr  y 


both  sides  (upper  and  lower)  of  the  finger  and  be  firmly 
cnougli  secured  to  tho  finger  to  keep  them  in  place,  without 
making  the  finger  of  an  unwieldy  bulk,  and  at  the  same  time 
allow  the  force  to  be  applied  upon  the  center  of  the  finger 
rather  than  upon  one  side  ? The  answer  is  this  : the  muscle 
which  sends  its  tendons  to  the  second  phalanx  lies  above  tho 
other  set  of  tendons,  and  Avhere  tho  superior  tendons  join  tho 
second  phalanx,  they  are  each  split  into  two  parts,  through 
which  the  tendons  of  tho  lower  muscle  pass  to  the  last  pha- 
lanx, and  move  freely  without  interruption  from  the  superior 
muscle  or  tendons.  This  arrangement  is  found  in  the  foot, 
as  well  as  in  the  hand,  for  giving  the  same  motion  to  tho 
toes,  and  very  much  resembles  the  movement  of  a cord 
through  a loop. 

246.  Muscles  of  the  Thumb  and  Little  Finger. — The 
/ thumb  and  little  finger,  as  already  mentioned,  are  supplied 
‘ with  separate  muscles  in  the  body  of  the  hand,  mainly  for  the 
purpose  of  giving  motion  from  side  to  side,  as  well  as  a partial 
rotation.  In  addition  to  this,  there  are  several  muscles  upon 
the  fore-arm  which  give  their  tendons  only  to  these  two  ex- 
tremities. The  obvious  use  of  this  arrangement  is  to  give 
strength  and  great  variety  of  motion  so  necessary  in  the 
thumb  and  little  finger. 

yi  247*  Muscles  of  the  Back,  Dorsal  Muscle. — Upon  the 
back  are  found  at  least  thirty  pairs  of  muscles,  which  are  ar- 
ranged in  six  layers.  These  are  of  various  forms  and  sizes, 
with  complicated  and  obscure  attachments.  The  main  use  of 
these  muscles,  taken  as  a group,  is  to  keep  the  trunk  in  an 
upright  position,  and  give  a firm  attachment  for  muscles  to 
move  the  extremities.  The  outermost  layer  is  very  super- 
ficial, lying  directly  under  the  skin,  while  the  deepest  layer 
is  deeply  imbedded  between  different  processes  of  the  vertebrae. 

Why  must  ono  tendon  pass  through  another  rather  than  pass  along  by  its  side? 
Do  wo  find  this  arrangement  ujion  hotli  liands  and  feet?  246.  Which  two  extremities 
of  tho  hand  have  tlio  mo>t  muscles  given  to  them?  247.  ITow  many  pairs  of  muscles 
upon  tlic  hack  of  tho  body?  Givo  tho  number  of  layers  into  which  they  maybe  <iis» 
•ected.  State  tho  essential  purpose  of  thorn. 


AND  PHYSIOLOGY 


123 


I'lG.  139. 


A View  of  the  Second  Layer  of  Muscles  of  the  Back.  1,  Trapezius.  2,  A portion  of 
the  Tendonous  ellipse  formed  by  the  Trapezius  on  both  sides.  8,  Spine  of  the  Scapula. 
4,  Latissimus  Dorsi.  5,  Deltoid.  6,  Infra-Spinatus  and  Teres  Minor.  7,  External  Ob- 
lique of  the  Abdomen.  8,  Glutens  Medijis.  9,  Gluteus  Magnius  of  each  side.  10,  Leva- 
tor Scapiilje.  11,  Ehomboicfeus  Minor.  12,  Ehomboideus  Major.  13,  Splenius  Capitis. 
14,  Splenius  Colli.  15,  A portion  of  the  Origin  of  the  Latissimus  Dorsi.  16,  Serratus  In- 
ferior Posticus.  17,  Supra-Spinatus.  IS,  Infra-Spinatus.  19,  Teres  Minor.  20,  Teres 
Major.  21,  Long  Head  of  the  Triceps  Extensor  Cubiti.  22,  Serratus  Major  Anticus.  23, 
Internal  Oblique  of  the  Abdomen. 

The  largest  muscle  of  the  back  (hence  the  name  Dorsal)  is 
of  value  to  move  the  arms.  It  has  its  origin  from  the  lum- 
bar and  sacral  vertebrae,  and  the  posterior  third  of  the  crest 
of  the  ilium,  and  is  inserted  by  a short  tendon  into  the  upper 
extremity  of  the  humerus.  The  action  of  this  muscle  brings 


Give  the  origin  and  insertion  of  the  Dorsal  muscle.  State  its  action. 


124 


HITCHCOCK’S  ANATOMY 


the  arm  downwards  and  backwards,  as  in  the  movements  of 
chopping  wood  or  striking  with  the  blacksmith’s  sledge.  But 
when  the  hands  arc  made  the  fixed  points,  the  body  is  raised 
upwards. 

j/"  ■ 248.  Superior  and  Inferior  Serrali. — Two  muscles  of  the 
back  are  used  in  forced  or  violent  respiration.  These  arc  the 
Superior  and  Inferior  Serrati  Muscles.  The  Superior  Scr- 
ratus  arises  from  the  three  lower  cervical  and  two  upper  dorsal 
vertebrae,  and  runs  downwards  and  forwards  to  be  inserted 
into  the  border  of  the  second,  third,  and  fourth  ribs.  The 
Inferior  Serratus  arises  from  the  last  two  dorsal  and  three 
upper  lumbar  vertebrae,  and,  running  upwards  and  forwards, 
is  inserted  upon  the  four  lower  ribs.  The  name  of  these  mus- 
cles means  in  Latin  saw-like,”  since  the  portions  which  join 
upon  the  ribs  resemble  the  teeth  of  a saw.  The  former  of 
these  elevates  the  ribs,  thereby  enlarging  the  cavity  of  the 
chest,  while  the  latter  assists  in  its  compression  by  depressing 
the  ribs,  and  consequently  the  diaphragm,  downwards. 

^ 249.  The  Diaphragm, — But  the  essential  muscle  of  respi- 

ration is  the  Diaphragm.  This,  as  its  name  implies,  is  a par- 
tition across  the  body  just  below  the  lungs, — with  three 
large  openings, — which  separates  the  thorax  from  the  abdo- 
men. Its  attachments  in  general  terms  may  be  said  to  be 
upon  an  oblique  lino  drawn  about  the  body  just  below  the 
ribs,  which  line  intersects  the  first  lumbar  vertebra,  where 
the  central  tendon  of  the  Diaphragm,  as  it  is  termed,  is  at- 
tached. When  relaxed,  it  presents  the  appearance  of  an  in- 
verted and  irregularly  shaped  cup  or  basin,  but  when  in  a 
state  of  contraction  it  becomes  nearly  a plane  surface.  Hence 
this  muscle  enlarges  the  chest  by  depressing  its  lower  surface, 
thereby  forming  a partial  vacuum. 


21S.  WHiIch  nuisck'3  of  tlic  back  arc  used  in  forced  respiration?  Give  the  origin  and 
Insertion  of  the  two  Serrate  Muscles.  Why  called  “Serrate?”  249.  Give  tlie  form  of 
the  Diaphragm.  Wliat  two  cavities  of  the  body  does  it  separate?  W'hat  Is  it  an  essen- 
tial agent  In  effecting  ? 


AND  PHYSIOLOGY, 


125 


Tig.  140. 


A Yiew  of  the  Under  Side  of  the  Diaphragm.  1,  2,  8,  The  Greater  Muscle  of  the  Dia- 
phragm inserted  into  the  Cordiform  Tendon.  4,  The  small  triangular  space  behind  the 
Sternum,  covered  only  by  Serous  Membrane,  and  through  which  Hernia  sometimes 
pass.  5,  Ligamentum  Arcuaturn  of  the  Left  Side.  6,  Point  of  Origin  of  the  Psoas  Mag- 
nus. 7,  A small  Opening  for  the  Lesser  Splanchnic  Nerve.  8,  One  of  the  Crura  of  the 
Diaphragm.  9,  Fourth  Lumbar  Vertebra.  10,  Another  Crus  or  portion  of  the  Lesser 
Muscle  of  the  Diaphragm.  11,  Hiatus  Aorticus.  12,  Foramen  <Esophageum.  13,  Fora- 
men Quadratum.  14,  Psoas  Magnus  Muscle.  15,  Quadratus  Lumborum. 

250.  Intercostal  Muscles. — Between  the  ribs  are  placed 
two  sets  of  muscular  fibres,  an  external  and  an  internal,  called 
the  Intercostal  Muscles,  which  by  their  action  draw  the  ribs 
upwards.  The  fibres  run  in  a diagonal  direction  from  one  rib 
to  another,  so  that  the  greatest  length  may  be  given  for  their 
contraction  without  compromising  too  much  of  their  power. 
And  hence  we  can  see  that  while  the  first  rib  is  firm  and  im- 
movable, by  contraction  of  these  fibres  the  ribs  must  be  raised, 
and  by  their  relaxation  they  must  be  depressed.  The  exter- 
nal fibres  run  downwards  and  towards  the  middle  line  of  the 
abdomen,  while  the  internal  run  downwards  and  backwards. 

251.  Abdominal  Muscles. — The  principal  muscles  of  the 
abdomen  are  large  and  thin  expansions  of  muscular  fibres, 

250.  Give  the  arrangement  of  fibres  in  the  Intercostal  Muscles.  251.  What  forms  the 
principal  part  of  the  walls  of  the  abdomen  2 


126 


II  I T C ]I  C O C K ’ 8 A N A T O ]M  Y 


Fig.  141. 


A Lateral  Yiew  of  the  Muscles  of  the 
Trunk,  esi)ecially  on  the  Abdomen.  1, 
Latissimus  Dorsi.  2,  Serratus  Major  An- 
ticus.  3,  Upper  portion  of  the  External 
Oblique.  4,  Two  of  the  External  Inter- 
costal Muscles,  5,  Two  of  the  Internal 
Intercostal  Muscles.  6,  Transversalis  Ab- 
dominis. 7,  Fascia  Lumborum.  8,  Poste- 
rior part  of  the  Sheath  of  the  Pectus,  or 
Anterior  Aponeurosis  of  the  Transversalis 
Muscle.  9,  The  Rectus  Abdominis  cut  off 


which  completely  cover  the 
space  below  the  border  of  tlio 
ribs,  and  above  the  innomina- 
tum.  They  are  arranged  un- 
der four  different  names,  since 
they  run  in  different  direc- 
tions as  they  encircle  the  ab- 
domen. By  their  contraction 
they  press  upon  the  digestive 
organs,  and  thus  diminish  the 
cavity  of  the  abdomen,  and, 
in  proportion  to  the  elasticity 
of  the  diaphragm,  the  thorax 
also.  Hence  these  are  the 
essential  instruments  in  cough- 
ing, laughing,  crying,  and 
sneezino;,  as  well  as  in  sino;- 
ing,  shouting,  or  any  action 
requiring  expulsive  effort.  By 
their  elasticity  they  also  per- 
form the  function  of  expira- 
tion in  natural  breathing,  as 
well  as  keep  up  a tonic  pres- 
sure upon  the  stomach  and 
alimentary  canal. 

252.  Great  Psoas  Muscle. 

— The  Great  Psoas  Muscle, 


and  in  its  Sheath.  10,  Rectus  Abdominis 
of  the  Ris:ht  Side.  11,  Crural  Arch.  12, 
Gluteus  Magnus— Medius  and  Tensor  Va- 
ginas Femoris  covered  by  the  Fascia  Lata. 

one  which  bends  the  thigh 


known  in  animals  as  the  ten- 
der loin  (from  the  Greek 
signifying  a loin),  is  the 
upon,  or  towards  the  trunk. 


It  has  its  origin  from  the  last  dorsal  and  four  upper  lum- 


bar vertebrae,  and  passes  from  thence  downwards  and  for- 
wards, gliding  over  the  edge  of  the  innominatum,  and  attaches 


Under  how  many  heads  are  they  arranged?  What  actions  do  they  accomplish  when 
contracted?  252.  What  is  the  scientific  name  of  the  “tender  loin?’’  Give  its  attach- 
ments. 


AND  PHYSIOLOGY 


127 


Fig.  142. 


A View  of  the  Superficial  Muscles  of  the  Left  Side,  and  of  the  Deep  Muscles  of  the 
Light  Side,  on  the  Front  of  the  Trunk.  1,  Pectoralis  Major.  2,  Deltoid.  8,  Anterior 
Edge  of  Latissimns-Dnrql.  4,  Serrated  Edge  of  Serratus  Major  Anticus.  5,  Subclavius 
Muscle.  6,  Pectoralis  Minor.  7,  Coraco-Brachialis.  8,  Biceps  Flexor  Cubiti.  9,  Cora- 
coid Process  of  the  Scapula.  10,  Scrtatus  Major  Anticus  after  the  removal  of  the  Ob- 
liquus  Externus  Abdominis.  11,  External  Intercostal  Muscle  of  the  Fifth  Intercostal 
Space.  12,  External  Oblique  of  the  Abdomen.  13,  Its  Tendon.  The  Median  Line  is  the 
Linea  Alba. — The  Line  to  the  Eight  of  the  Number  is  the  Linca  Semilunaris.  14,  The 
portion  of  the  Tendon  of  the  External  Oblique,  known  as  Poupart's  Ligament.  15,  Ex- 
ternal Abdominal  Eing.  16,  Eectus  Abdominis.  The  White  Spaces  are  the  Linea  Trans- 
versaj.  17,  Pyramidalis.  18,  Internal  Oblique  of  the  Abdomen.  19,  Common  Tendon 
of  the  Internal  Oblique  and  Transversalis.  20,  Crural  Arch.  21,  Fascia  Lata  Femoris. 
22,  Saphenous  Opening.  The  Crescentic  Edge  of  the  Sartorial  Fascia  is  seen  just  above 
fig.  22,  and  the  Interior  or  Pubic  Point  of  the  Crescent  is  known  as  Hey’s  Ligament. 


itself  to  the  front  part  of  the  lesser  trochanter  process  of  the 
femur.  It  is  made  up  of  a very  compact  band  of  fibers,  and, 
though  acting  at  a great  mechanical  disadvantage,  it  is  ca- 
pable of  moving  the  lower  extremity  with  great  power.  By 

6* 


128 


HITCHCOCK’S  ANATOMY 


this  muscle  it  is  that  the  body 
is  fixed,  and  also  by  its  means 
in  a sitting  posture. 

253.  Gluteus  Muscle— A 


Pig.  143. 


A Tiew  of  the  Muscles  on  the  Front  of 
the  Thigh,  1,  Crest  of  the  Ilium.  2,  Its 
Anterior  Superior  Siunous  Process.  3, 
jG  1 n (1  i ii s.  4,  Tensor  Vaginae  Fe- 
inoris.  5,  Sartoiius.  C,  Pectus  Feinoris. 
7,  Vastus  Fxterntis.  8,  Vastus  Internus. 
1),  Patella.  10,  Iliacus  Internus.  11,  Psoas 
Magnus.  12,  Pectlncus,  13,  Adductor 
Longus.  14,  Adductor  Magnus.  15,  Gra- 
cilis, 


is  bent  forward  when  the  thigh 
we  keep  the  body  erect  when 

movement  in  a direction  oppo- 
site to  the  last  muscle,  is  ef- 
fected by  the  contraction  of 
the  Gluteus  muscle.  This 
has  its  origin  and  insertion  at 
points  directly  opposite  to 
those  of  the  psoas  muscle — 
and  forms  the  nates  or  but- 
tock. The  fibers  of  this  mus- 
cle are  the  coarsest  of  any  in 
the  whole  body,  showing  that 
they  are  designed  for  strength 
and  not  celerity  of  motion. 
Besides  the  movement  already 
mentioned,  this  muscle  is  of 
great  value  when  the  leg  is 
made  firm  by  keeping  the 
body  in  an  upright  position, 
or  raising  the  body  upon  the 
thighs  when  it  is  bent  forward. 

254.  Muscles  of  the 
Thigh. — The  leg  (Tibia)  is 
moved  upon  the  thigh  (Fe- 
mur) by  the  conjoint  action 
of  four  muscles.  These  have 
their  origin  about  the  head  of 
the  femur,  and  the  lower  por- 
tion of  the  innominatum,  and 
all  unite  into  one  tendon 
which  is  inserted  upon  the 
tubercle,  or  process  of  the 


What  movements  3iro  clTected  by  it?  253.  What  muscle  produces  motion  in  a con- 
trary direction  to  the  psoas  muscle  ? What  is  said  of  the  size  of  the  fibers  of  the  Gluteus  ? 
254.  How  many  muscles  act  to  extend  the  tibia  or  the  femur? 


AND  PHYSIOLOGY. 


129 


tibia  near  to  its  upper  extremity.  Spoken  of  together,  these 
muscles  are  called  the  Quadriceps  Extensor  Femoris.  The 
tendon  is  one  of  the  strongest  in  the  body,  and  has  inclosed 
within  it  the  patella,  which  bears  the  same  relation  to  the 
tendon  as  the  pulley  does  to  the  cord  which  passes  over  it. 
The  action  of  these  muscles  extends  the  leg,  as  in  walking, 
running,  or  lifting  the  foot,  and  also  places  the  femur  in  a line 
above  the  tibia,  when  the  latter  is  made  the  fixed  point. 

255.  Sartorius  Muscle. — The  Sartorius  or  Tailor’s  mus- 
cle is  a very  long  and  slender  muscle  commencing  at  the  an- 
terior portion  of  the  innominatum,  and,  descending 

and  inwards,  is  inserted  into  the  upper  part  of  the  inside  of 
the  tibia.  The  obvious  action  of  this  muscle  will  be  to  bend 
the  leg  somewhat  backwards,  and  then  to  carry  it  across  its 
fellow,  as  is  done  by  the  tailor  when  seating  himself  for  work 
on  his  bench. 

256.  Tensor  VagincB  Femoris. — A muscle  already  alluded 
to — the  Tensor  Vaginae  Femoris,  or  stretcher  of  the  sheath  of 
the  thigh — arises  at  the  upper  and  front  portion  of  the  inno- 
minatum, and  is  inserted  into  the  very  strong  fasciae  of  the 
thigh,  its  use  being  to  assist  the  muscles  in  their  action,  by 
increasing  the  tonic  pressure  upon  them. 

257.  Muscles  of  the  Posterior  Part  of  the  Thigh. — 
The  muscles  found  upon  the  posterior  part  of  the  femur 
and  antagonizing  the  compound  muscle  in  front,  are  four  in 
number,  taking  their  origin  from  the  ischium  and  pubes,  and 
being  inserted  into  the  broad  head  of  the  tibia.  Their  ten- 
dons make  those  portions  of  the  thigh  which  are  familiarly 
known  as  the  ham-strings.  Their  names  are  the  Biceps, 
Gracilis,  Semi-tendinosus  and  Semi-membranosus. 


When  taken  together,  what  is  the  muscle  called  ? What  bone  is  imbedded  in  the  ten? 
don  of  the  Quadriceps  Extensor  Femoris  ? 255.  Describe  the  Sartorius  or  Tailor’s  mus- 
cle. 256.  What  is  the  Tensor  Vaginae  Femoris  of  service  for?  257.  Uow  many  muscles 
act  as  antagonists  to  the  Quadriceps,  etc.  ? Give  their  names. 


130 


HITCHCOCK’S  ANA  T O M Y 


Fig.  144. 


A View  of  the  Muscles  on  the  Back  of 
the  Thigh.  1,  Cliiteiis  Medius.  2,  Gl]j- 
teusMngnus^  8,  Fascia  Lata  covering  the 
YastusTTxternus.  4,  Long  Head  of  the 
Biceps.  6,  Short  Head  of  the  Biceps.  6, 
Senii-Tendinosus.  7, 7,  Semi-Meinbranosus. 
?E7^racilis.  9,  Edge  of  the  Adductor  Mag- 
nus. 10,  Edge  of  the  Sartorius.  11,  Pop- 
liteal Space.  12,  Gastrocnemius. 


Fig.  145. 


A View  of  the  Muscles  on  the  Front  of 
the  Leg.  1,  Tendon  of  the  Quadriceps 
Femoris.  2,  Spine  of  the  Tibia.  3,  Tibi- 
alis Anticus.  4,  Extensor  Communis  Digi- 
torum.  5,  Extensor  Proprius  Pollicis.  6, 
Peroneus  Tertius.  7,  Peroneus  Longus. 
8,  Peroneus  Brevis.  9,  9,  Borders  of  the 
Soleus.  10,  Portion  of  the  Gastrocnemius. 
11,  Extensor  Brevis  Digitorum. 


258.  Muscles  of  the  Anterior  Part  of  the  Leg. — Upon 
llie  anterior  portion  of  the  Tibia,  or  leg  proper,  are  found  four 
muscles  'with  slender  tendons,  'which  are  for  the  up'ward  move- 
ment or  flexion  of  the  foot.  They  have  their  origin  near  the 
head  of  the  tibia,  and  arc  inserted  into  the  bones  of  the  meta- 

2r)8.  "Whore  are  tho  four  muitcles  located  that  bend  the  foot  upward  ? Give  their  origin 
and  ineerUgn. 


AND  PHYSIOLOGY. 


131 


tarsus  and  phalanges.  Their 
names  are  the  Tibialis  Anti- 
cus,  Extensor  Longus  Eigi- 
torum,  Peroneus  Tertius,  and 
Extensor  Proprius  Pollicis. 

259.  Muscles  of  the  Pos- 
terior Part  of  the  Leg— The 
muscles  on  the  reverse  por- 
tion of  the  leg  are  three,  con- 
stituting what  is  known  as  the 
calf  of  the  leg.  They  are  the 
Gastrocnemius,  Plantaris,  and 
Soleus.  They  are  attached  to 
the  top  of  the  tibia  on  its  pos- 
terior side,  as  well  as  to  the 
lower  part  of  the  femur,  and 
all  form  a conjoint  tendon,  the 
largest  in  the  body,  and  which 
is  attached  to  the  bone  of  the 
heel.  It  is  called  the  tendon 
of  Achilles,  because  the  great 
Grecian  warrior  is  said  to  have 
been  killed  by  the  wound  of 
an  arrow  at  this  point.  The 
use  of  these  muscles  is  to  raise 
the  body  upon  the  toes,  and 
are  the  muscles  which  are  of 
the  greatest  value  to  us  in  the 
act  of  walking.  Immediately 
beneath  these  muscles  are  six 
an  opposite  direction  to  those 
leg.  They  are  attached  near 
fibula,  and  inserted  into  the 


Fig.  146. 


A View  of  the  Muscles  on  the  Back  of  the 
Leg.  1,  Tendon  of  the  Biceps.  2,  Inner 
Hamstring  Tendons.  8,  Popliteal  Space. 
4,  Gastrocnemius.  5,  Soleus.  G,  Tendo- 
Achillcs.  7,  Its  Insertion  on  the  Os  Calcis. 
8,  Tendons  of  the  Peroneus  Longus  and 
Brevis.  9,  Tendons  of  the  Tibialis  Posti- 
cus and  Flexor  Longus  Digitorum  behind 
the  Internal  Malleolus. 

others  which  produce  motion  in 
upon  the  anterior  portion  of  the 
the  upper  part  of  the  tibia  and 
metatarsal  bones  and  the  pha- 


259.  State  the  muscles  which  constitute  the  calf  of  the  leg.  What  is  Tendon  of  Achil- 
les, and  why  is  it  so  called  ? IIow  many  muscles  lie  deeply  covered  in  the  calf  of  the 
Ifeg? 


132 


HITCHCOCK’S  ANATOMY 


langes.  In  the  tendon  of  one  of  them  (Peroncus  Longus)  is 
found  a sesamoid  bone,  at  the  point  where  it  glides  over  the 
cuboid  bone. 

260.  Muscles  of  tlic  Fool. — A few  muscles  are  found 
upon  the  upper  and  under  surface  of  the  foot,  most  of  which 

arise  near  the  tarsus,  and  are 
inserted  at  the  base  of  the 
phalanges.  In  their  action 
the  toes  are  either  bent  or 
extended. 

261.  Annular  ligaments. 
— An  interesting  contrivance 
for  preserving  the  slenderness 
of  the  hand  and  foot  is  found 
in  the  Annular  Ligaments. 
These  are  large  bundles  of 
ligamentous  tissue  which  pass 
around  the  wrist  and  ankle, 
very  much  resembling  a brace- 
let. (Figs.  148,  and  149,  p. 
183.)  They  are  very  firm  and 
stout,  and  their  design  is  to 
keep  in  place  the  tendons 
Avhich  move  the  extremities. 
When,  for  example,  we  move 
the  toes  upwards,  the  muscles 
which  effect  this  motion  with 
their  tendons  would  extend  in  a straight  line  from  the  upper 
part  of  the  tibia  to  the  last  phalanx,  thus  making  the  leg 
and  foot  very  cumbersome  and  unwieldy  organs,  and  poorly 
adapted  to  their  present  use. 


Fio.  147. 


A Yiew  of  the  Muscles  on  the  Sole  of  the 
Foot  immediately  under  the  Plantar  Fas- 
cia. 1,  Os  Calcis.  2,  Section  of  the  Fascia 
Plantaris.  3,  Abductor  Pollicis.  4,  Ab- 
ductor Minimi  Digiti.  5,  Flexor  Brevis 
Digitorum.  6,  Tendon  of  the  Flexor 
Longus  Pollicis.  7,  7,  Lumbricales. 


201.  WliAt  is  the  use  of  the  Annular  Ligaments?  What  ornaments  do  they  very  closely 
resemble  ? Suppose  these  or  their  equivalent  was  wanting  ? 


A]^D  PHYSIOLOGY 


133 


Tig.  148. 


Fig.  149. 


A View  of  the  Outer  Layer  of  Muscles 
on  the  Back  of  the  Fore- Arm  (Extensors). 

1,  Lower  portion  of  the  Biceps  Flexor.  2, 

Part  of  the  Brachialis  Interniis.  3,  Lower 
part  of  the  Triceps  Extensor.  4,  Supinator 
Eiidii  Longus.  5,  Extensor  Carpi  RadialLs 
Longior.  6,  Extensor  Carpi  Radialis  Bre- 
vier. 7,  Tendinous  Insertions  of  these  two 
Muscles.  S,  Extensor  Communis  Digito- 

rum.  9,  Portion  of  the  Extensor  Communis  Bigitorum  called  Auricularis.  10, 
Extensor  Carpi  Ulnaris.  11,  Anconeus.  12,  Portion  of  the  Flexor  Carpi  Ulnaris. 
13,  Extensor  Minor  Pollicis.  The  Muscle  nearest  the  Figure  is  the  Extensor  Ossis 
Metacarpi  Pollicis.  14,  Extensor  Major  Pollicis.  17,  Posterior  Annular  Ligament. 
The  distribution  of  the  Tendons  of  the  Extensor  Communis  is  seen  on  the  backs  of 
the  Fingers. 


A View  of  the  Muscles  on  the  Front  of 
the  Leg.  1,  Tendon  of  the  Quadriceps 
Femoris.  2,  Spine  of  the  Tibia.  3,  Tibi- 
alis Anticus.  4,  Extensor  Communis  Bigi- 
torum. 5,  Extensor  Proprius  Pollicis.  6, 
Peroneus  Tertius.  7,  Peroneus  Longus. 
8,  Peroneus  Brevis.  9,  9,  Borders  of  the 
Soleus.  10,  Portion  of  the  Gastrocnemius. 
11,  Extensor  Brevis  Bigitorum. 


134 


HITCHCOCK’S  ANATOMY. 


FUNCTIONS  OF  THE  MUSCLES. 

262.  Irritability  of  Muscular  Fiber.— Muscular  fiber  has 
one  characteristic  peculiar  to  this  tissue.  This  is  known  as 
Irritability  or  Myotility,  the  shortening  of  the  fiber  when  a 
stimulus  is  applied.  The  stimulus  may  be  mechanical,  as 
when  the  legs  of  a grasshopper  are  irritated  with  a probe  or 
some  pointed  instrument,  it  produces  contractions.  Electric 
and  galvanic  currents,  also,  when  made  to  pass  interrupt- 
edly through  any  muscular  portions  of  the  body  produce  con- 
tractions ; as  when  a person  grasps  the  handles  of  an  electro- 
tome or  seizes  the  ball  of  a Leyden  jar.  And  lastly,  vitality 
is  a muscular  stimulus. 

Fig.  150.  263.  Condition  of  the  Fibrils  in  a State 

of  Contraction . — Formerly  it  was  supposed 
that  muscular  contractions  w^ere  due  to  a 
zig-zag  position  which  was  assumed  by  the 
fibrils  ; but  microscopical  examination  has 
proved  that  the  shortening  of  the  fiber  is 
owing  to  a change  in  the  diameter  of  the 
ultimate  fibrils ; the  cell  in  the  fibril  at 
rest  having  its  longest  diameter  parallel  to 
the  fiber,  w^hile  in  a state  of  contraction  the 
longest  diameter  is  at  right  angles  to  this. 

264.  Tonicity . — Another  characteristic 
of  muscular  fiber  is  Tonicity.  This  is  a 
constant  strain  or  stretch  of  the  muscular 
fiber,  while  irritability  or  contractility  only 
structure  of  the  Fi-  manifests  itself  when  a stimulus  is  applied. 

Lnllic.  a,  A fibril  m 

tiie  state  of  ordinary  re-  Tliis  is  a property  whicli  is  exhibited  when 

laxaMon.  h,  A fibril  i i i i r'l 

partially  contracted.  ^ bonc  IS  broken  or  some  muscular  nbers 
arc  separated.  Thus,  when  a cut  is  made 


2C2.  What  is  the  prominent  characteristic  of  muscular  tissue?  Illustrate  the  mechan- 
ical, electric,  and  vital  stimuli.  268.  How  do  the  cells  of  the  fibrils  arrange  themselves 
durinpr  a contracted  state?  264.  What  Is  understood  by  Muscular  Tonicity?  When  is 
ihla  only  manifest  ? 


AND  PIIYSIOLOGA", 


135 


directly  across  the  fibers  the  gash  at  once  opens  very  widely ; 
or  if  a bone  is  broken  and  the  ends  allowed  to  slide  by  each 
other,  it  is  only  by  great  force  that  they  can  be  brought  back 
to  their  proper  places.  The  value  of  this  property  is  seen  in 
keeping  the  muscles  in  a state  ready  for  action,  as  well  as  in 
assisting  the  ligaments  to  keep  the  joints  firmly  together. 

265.  Dependent  on  Vital  Energy —Both  of  these  charac- 
t:!ristics  are  dependent  upon  nervous  or  vital  energy.  For  if 
life  be  extinct,  or  the  nerve  proceeding  to  any  muscle  be  cut 
off,  tonicity  and  irritability  soon  cease  ; although  they  remain 
for  a longer  time  in  the  involuntary  than  the  voluntary  mus- 
cles. As,  for  example,  the  heart  of  a sturgeon,  after  its  re- 
moval from  the  body,  has  been  known  not  only  to  pulsate  for 
a short  time,  but  even  to  keep  up  its  action  until  its  folds 
fairly  rustled  from  inherent  dryness. 

266.  Muscular  Waste  the  Cause  of  Muscular  Contrac- 
tion.— But  here  the  question  meets  us.  What  is  this  power  that 
passes  through  the  nerves  to  each  fibril,  and  how  does  it  energize 
the  muscle  ? Is  it  a fluid  acting  on  the  fibers  in  the  same  manner 
that  water  acts  upon  the  strands  of  a rope,  or  is  it  an  impon- 
derable agency,  like  electricity  or  heat,  passing  through  the 
nerve  by  polar  attraction  or  conduction  from  particle  to  par- 
ticle ? At  present  we  must  rest  with  the  facts  of  muscular 
movement,  and  perhaps  we  can  never  solve  the  mystery  in 
this  world.  The  nature  of  what  we  vaguely  denominate 
nervous  or  vital  force  has  never  been  determined.  No  mys- 
tery in  religion  exceeds  that  of  muscular  movement.  It  how- 
ever seems  to  be  the  case  that  muscular  contraction  is  in  a good 
degree  dependent  on  a due  degree  of  arterialization  of  the 
blood  ; for  if  a muscle  be  placed  in  carbonic  acid  its  irritability 
soon  ceases,  while  in  oxygen  it  remains  a long  time  after  it  is 
removed  from  the  body.  A want  of  the  proper  amount  of  oxy- 


Of  vrhat use  is  this  property?  265.  Upon  what  do  both  myotility  and  tonicity  depend ? 
In  which  muscles  do  they  remain  the  longest  after  death  ? Instance  the  heart  of  the  stur- 
geon. 266.  What  is  all  we  know  of  the  power  that  produces  this  contraction  ? 


13G 


niTc  II  cock’s  anato^siy 


gen  is  the  cause  of  the  inability  to  exertion  experienced  in  the 
thin  air  of  mountain  tops  and  the  relaxation  of  the  muscles  in 
fainting  from  exposure  to  carbonic  acid,  ether,  or  chloroform. 
On  the  other  hand,  the  more  full  the  respiration,  the  more  ener- 
getic the  muscular  power.  The  effect  of  oxygen  upon  the  tis- 
sues is  that  of  waste,  or  a consumer  ; that  is,  it  produces  a more 
rapid  circulation  of  matter  by  removing  the  carbonic  acid, 
and  substituting  itself  in  its  place  ; and  the  deeper  the  respi- 
ration, the  more  energetically  will  all  the  functions  of  the 
body  be  carried  on.  Hence  a plausible  theory  offers  itself 
to  explain  the  cause  of  muscular  contraction,  which  is,  that 

muscular  contraction  is  the  necessary  physical  result  of  mus- 
cular disintegration.’’ 

267.  The  Mechanical  Disadvantage  at  which  many 
Muscles  Act  — The  Reason  of  it. — The  force  of  muscular 
contractions  is  almost  always  very  great,  sometimes  so  pow- 
erful that  some  of  the  fibers  are  ruptured.  But  the  main 
evidence  of  this  great  force  is  exhibited  in  the  mechanical  dis- 
advantage at  which  most  of  the  muscles  act.  For  instance, 


if  the  muscles  were 
attached  at  c,  a much 
greater  weight  could 
be  lifted  by  the  ex- 
penditure of  the  same 
power  than  if  it  were 


Fig.  151. 


attached  at  b ; but  a much  longer  portion  of  time  would  be 
necessary  to  produce  contraction  in  such  a length  of  fiber,  a 
c,  than  in  a shorter  portion,  a 6.  Besides,  in  most  cases  it 
ivould  be  quite  impossible  for  the  muscles  to  contract  suffi- 
ciently to  effect  what  they  now  do,  since  muscular  fiber  can 
not  shorten  itself  more  than  one  third  of  its  whole  length,  as 
measured  when  uncontracted,  or  in  a state  of  rest. 


Wlmt,  however,  do  we  know  nhout  deficiency  of  oxygen  as  affecting  these  properties? 
Instance  ether  and  cliloroforrn  also.  What  liypothesis  has  been  suggested  owing  to  the 
waste  produced  by  oxygen  ? 267.  How  is  muscular  power  well  illustrated?  What  loss 
and  whut  gain  are  both  experienced  by  this  construction  ? 


AND  PHYSIOLOGY. 


137 


268.  Contraction  commences  at  one  End — Only  a Part 

of  the  Fibrils  in  a State  of  Contraction  at  Once. — The 
contraction  of  a muscle  does  not  take  place  in  all  parts  of  the 
fibers  at  the  same  time,  but  commences  at  one  end,  and  con- 
tinues through  in  regular  Piq,  152. 

order,  as  is  seen  in  the 
cut  152.  It  is  also  sel- 
dom the  case  that  all  the 
fibers-  are  contracted  at 
once.  This  explains  the 
reason  why  insane  people 

« T . T Muscular  Fiber  contracting,  a,  Uncontracted 

are  often  so  prodigiously  part.  5,  Contracted  part, 
strong,  since  the  whole  of  the  muscle  is  made  to  act  at  once. 
It  also  shows  us  why  we  can  keep  a muscle  contracted  for  a 
long  time,  as  in  carrying  a weight  for  a long  distance,  and 
also  why  a short  and  violent  muscular  action  weakens  and 
tires  us  more  than  a protracted  and  more  moderate  one.  The 
simple  explanation  is,  that  but  a part  of  the  fibrils  are  con- 
tracted at  once,  and  when  the  nervous  force  is  exhausted  from 
one  set  of  fibrils,  a new  set  are  called  into  action  to  supply 
their  power. 

269.  Examples  of  Muscular  Strength— As  examples  of 
great  muscular  strength,  we  have  given  to  us  the  history  of  a 
Samson  and  Goliath.  And  in  more  modern  times  we  read  of 
Milo  of  Crete  who  killed  an  ox  with  his  fist,  and  then  carried 
it  more  than  600  feet.  He  also  saved  the  life  of  his  fellow- 
scholars  and  teacher,  Pythagoras,  by  supporting  the  falling 
roof  until  they  had  time  to  escape.  Another  man  is  men- 
tioned Avho  could  raise  300  pounds  by  the  muscles  of  his  lower 
jaw.  This  strength,  however,  is  exhibited  much  more  strik- 
ingly in  another  part  of  this  chapter  under  the  head  of  Com- 
parative Myology. 


268.  Do  all  the  fibers,  or  even  all  portions  of  each  fiber  act  at  once  in  ordinary  cases? 
Instance  insane  people.  269.  Give  examples  of  great  muscular  strengh  as  illustrated  by 
Goliah  and  Milo. 


138 


HITCHCOCK’S  ANATOMY 


270.  Rapidity  of  Muscular  Contraction— The  rapidity 
of  muscular  movement  is  equally  wonderful.  The  pulsations 
of  the  heart  in  children  can  often  be  counted  as  high  as  200 
per  minute.  Some  persons  can  pronounce  1500  letters  in  a 
minute  (of  course  combined  in  words),  each  one  requiring  the 
contraction  and  relaxation  of  one  or  more  muscles,  and  both 
occupying  3 oVoth  of  a minute,  or  sVth  of  a second.  The 
muscles,  too,  which  move  the  wings  of  some  insects  must 
contract  many  thousands  of  times  every  second  in  order  to 
produce  the  musical  tone  or  humming  that  is  frequently  heard 
when  their  wings  are  in  motion. 

271.  Duration  of  Muscular  Contraction — Intrinsic  and 
Available  Force — Shortening  of  Muscular  Fiber— Muscu- 
lar Sense — Sound  and  Heat. — The  length  of  time  which 
muscles  may  be  on  the  stretch  is  astonishing,  but  especially 
so  among  the  lower  orders  of  animals  soon  to  be  mentioned. 

The  intrinsic  force  of  a muscle  is  no  measure  of  its  avail- 
able power.  Thus  the  deltoid,  if  able  to  act  in  a perpendicu- 
lar direction,  would  raise  1000  pounds ; while,  acting  at  the 
great  mechanical  disadvantage  (that  it  does)  of  passing  over  the 
head  of  the  humerus,  it  can  not  lift  50  pounds  held  in  the 
hand. 

The  amount  of  shortening  of  the  fiber  in  muscular  contrac- 
tion is  differently  stated  by  physiologists.  The  statements 
are  from  one  third  to  one  sixth  the  length  of  the  muscle. 
That  is,  a muscle  three  inches  long  can  by  contraction  be- 
come only  two  inches,  or  one  six  inches  long  become  five 
inches.  It  is  probable,  however,  that  the  former  statement  is 
the  nearest  to  the  truth,  and  that  a muscle  is  shortened  from 
one  half  to  one  third  its  original  length. 

The  muscles  give  but  little  evidence  of  sensibility ; that  is, 
perception  of  objects  by  pressure  or  touch ; but  when  fatigued  oV 
overworked,  they  give  a painful  sensation,  and  also  give  to  theh 

270.  State  instances  of  great  rapidity  of  muscular  movement,  as  in  pulsations  oi 
chllilren’s  licarts  and  the  power  of  articulating  words.  271.  State  the  distinction  be' 
tween  the  intrinsic  and  available  force  of  muscles.  IIow  much  does  muscular  fibei 
shorten  during  Its  contraction  ? What  is  muscular  sense  ? 


AND  PHYSIOLOGY. 


139 


possessor  a very  delicate  sense  of  the  amount  of  their  contrac- 
tions. 

It  is  also  an  established  fact  that  a peculiar  rumbling  sound 
is  given  off  and  heat  evolved  during  muscular  contraction, 
the  latter  of  which  is  easily  explained  by  the  increased  mus- 
cular waste,  or  the  absorption  of  oxygen  and  evolution  of  car- 
bonic acid. 

272.  Preeisioii  of  Muscular  Contraction. — An  astonish- 
ing precision  in  contraction  of  muscles  is  seen  in  those  of  the 
human  larynx.  The  largest  of  these  muscles  is  less  than 
three  fourths  of  an  inch,  and  the  total  amount  of  contraction 
one  fifth.  And  since  the  ordinary  compass  of  the  human 
voice  is  two  octaves,  or  twenty-four  semi-tones,  and  ten  inter- 
vals between  each  of  the  contiguous  semi-tones  can  be  easily 
detected  by  a person  with  a cultivated  ear,  there  must  be  a 
shortening  of  only  jaVo^h  of  an  inch.  And  more  wonderful 
than  all  is  the  precision  and  readiness  with  which  an  ordinary 
singer  can  accurately  strike  one  note  after  another  with  inter- 
vals of  from  two  to  twenty-four  semi-tones. 


HYGIENIC  INFERENCES. 

273. — 1.  Muscles  need  Use . — The  muscles  should  be  used. 
This  is  necessary  to  stimulate  the  blood-vessels  and  lymphatics 
to  a healthy  action,  so  that  the  nutritious  particles  may  be 
deposited  in  proper  proportion,  and  the  waste  particles  be  re- 
moved ; in  other  words,  to  promote  that  constant  change 
which  in  all  the  organs  of  the  body  is  so  necessary  for  health. 
Their  moderate  use  also  promotes  their  growth  and  strength, 
while  inaction  causes  them  to  diminish  both  in  strength  and 
size. 


Speak  of  sound  and  heat  attendant  upon  muscular  contraction.  272.  What  remarkable 
precision  is  there  in  many  muscular  movements?  273.  Why  is  it  necessary  that  the 
muscles  be  used  to  a moderate  extent  ? 


140 


HITCHCOCK’S  ANATOMY 


274.  — 2.  Muscles  need  Rest, — The  muscles  also  need  rest. 
That  is,  after  work  they  need  repose  to  restore  the  energies 
which  they  have  expended,  and  if  the  amount  of  rest  which 
they  receive  is  not  sufficient  to  recruit  the  strength,  they  will 
soon  become  small  and  weak  ; for  the  lymphatics  are  so  stimu- 
lated that  the  amount  of  matter  removed  exceeds  what  is  de- 
posited. But  sleep  is  the  grand  restorative  after  severe  mus- 
cular exertion ; this  alone  gives  back  to  the  muscle  its  life 
and  strength. 

275.  — 3.  Muscles  should  Rest  gradually  after  Yiolcut 
Exercise. — Experience,  however,  shows  that  when  the  mus- 
cular system  has  been  exercised  vigorously  it  should  not  bo 
allowed  perfect  rest  at  once,  but  by  degrees.  Such  a course 
would  save  many  an  ache  and  stiff  joint  to  the  hard-working 
farmer  and  mechanic,  and  especially  to  the  one  wffio  labors 
till  the  body  is  in  a state  of  perspiration. 

276.  — 4.  Muscles  require  Regular  Exercise. — Labor  or 
exercise  that  is  regular  and  uniform  is  much  the  most  conducive 
to  health.  The  muscles  wdll  endure  a much  greater  amount 
of  effort  if  made  steadily,  rather  than  spasmodically.  Regu- 
larity of  action  is  important  in  every  function,  but  in  none 
more  evidently  so  than  the  muscles. 

277.  — 5.  Especial  want  of  Exercise  by  Students  and 
Sedentary  People. — We  see  that  students  and  other  seden- 
tary persons  are  in  special  need  of  physical  exercise,  and 
should  consider  it  a moral  duty  to  secure  it,  for  it  stimulates 
every  organ  to  a healthy  action.  The  blood  flows  more 
readily,  and  moi*e  completely  fills  all  the  minute  vessels ; the 
glands  of  the  skin  act  more  vigorously  ; the  lymphatics  and 
nutritive  vessels  perform  their  part  more  perfectly ; and  even 
the  nervous  system  is  kept  in  a healthy  state  by  exercise.  It 
is  best,  however,  to  get  exercise  if  possible  wdth  some  other 

2T1.  For  -vvliat  do  tho  muscles  of  hard-working  men  need  rest,  and  especially  sleep  ? 
275.  Is  it  always  best  to  gain  rest  at  once,  or  gradually  ? 27G.  What  kind  of  labor  or  ex- 

ercise Is  most  conducive  to  health?  277.  Vv'’hy  do  students  and  sedentary  people  stand 
greatly  in  need  of  muscular  exertion  ? Is  more  drudge  work  the  best  exorcise  ? 


AND  PHYSIOLOGY. 


141 


motive  than  a mere  conviction  of  its  necessity  and  importance. 
For  if  we  are  interested  in  pursuing  an  object,  the  mind  ac- 
quires a healthy  action,  and  by  its  reaction  brings  on  a state 
of  perspiration  in  the  body.  In  this  case  we  have  obtained 
two  ends,  the  muscular  system  has  been  exercised,  and  the 
mind  has  gained  full  recreation  from  study.  Hence  the  study 
of  natural  history,  and  especially  those  branches  of  it  which 
require  field  exercise  in  collecting  specimens,  not  only 
strengthens  the  mind  and  furnishes  new  objects  of  thought, 
but  is  an  admirable  method  of  gaining  bodily  strength. 

278. — 6.  Value  of  Gymnasia,  etc.,  to  Colleges  and  Acad- 
emies.— We  see  how  injurious  to  health  is  the  stimulating 
plan  adopted  in  too  many  of  our  higher  seminaries  of  learn- 
ing. The  mind  is  crowded  to  its  utmost  with  labor ; too 
much  time  is  taken  up  with  cultivating  the  intellect,  while 
the  body  is  left  to  take  care  of  itself.  A gymnasium  or 
some  equivalent  means  of  taking  exercise  is  as  important 
a thin^c  to  our  colleges  and  academies  as  are  the  build- 
ings,  libraries  and  cabinets  themselves.  And  may  it  not 
be  the  reason  why  literary  men  are  generally  so  great  suf- 
ferers from  ill  health,  that  so  little  attention  is  paid  to  physi- 
cal culture  during  the  preparatory  and  collegiate  course  ? 
Is  it  not  poor  economy  to  take  so  much  pains  to  cultivate  the 
inhabitant,  when  the  house  that  it  is  to  live  in  is  such  a mis- 
erable tenement,  and  receives  so  little  care  and  improvement  ? 


REMARKS  UPON  MUSCULAR  DEVELOPMENT. 

With  the  existing  customs  of  the  wealthier  classes  of 
society,  and  our  higher  seminaries  of  learning  especially,  it  is 
hardly  possible  to  say  too  much  upon  the  necessity  of  physical 
education  : not  that  it  is  best  to  lower  the  standard  of  intel- 


Why  does  the  study  of  some  branch  of  natural  history  secure  the  best  exercise  ? 278. 
What  is  said  of  the  effect  of  a neglect  of  muscular  exercise  in  schools  and  upon  many 
educated  men  of  our  country  ? 


142 


It  I T C II  C O C K ’ S A N A T O INI  Y 


Icctual  culture  in  the  least,  or  to  dictate  how  those  wl.o  are 
possessed  of  an  abundance  of  wealth  shall  dispose  of  it,  but 
simply  to  say  that  «a  thorough  physical  cducatSon  is  essential 
for  a proper  enjoyment  and  improvement  of  our  whole  nature, 
body,  mind,  and  soul.  The  evils  of  a neglect  of  this  branch 
of  education  exhibit  themselves,  not  only  in  puny  clergymen 
and  lawyers,  but  in  the  meager  and  attenuated  physiques  of 
our  mothers  and  sisters. 

Eoys,  especially  wlieyi  boys,  will  run,  jump,  shout,  ai.d 
be  in  the  open  air  in  spite  of  any  thing  but  the  closest 
watch  ; in  fact  it  is  thought  proper  that  boys  should  be  ruddy 
in  countenance  and  healthy,  but  with  girls  it  is  not  so. 
By  grossly  perverted  usages  of  society,  it  is  considered  im- 
proj)er  for  girls  to  run  and  jump  and  shout,  and  especially  so 
out  of  doors;  but  while  mere  children  even,  they  must  act  as 
young  ladies^  and  never  move  except  in  a precise  and  meas- 
ured manner,  often  as  unnatural  as  it  is  injurious;  and  any 
thing  that  requires  muscular  effort,  is  regarded  as  vulgar, 
and  of  course  not  to  be  undertaken.  Now,  physiology  tells 
us  that  just  the  thing  which  our  girls  and  ladies  stand 
in  need  of  at  the  present  day  is  active,  vigorous  muscular 
effort,  such  as  walking,  rowing,  riding  on  horse-back,  and 
calisthenic  and  gymnastic  exercises.  And  let  the  question 
be  suggested  to  parents,  guardians,  and  in  fact  all  inter- 
ested in  the  prosperity  or  even  the  existence  of  the  Anglo- 
Saxon  race  on  this  continent,  whether  the  physical  develop- 
ment of  ladies  shall  be  neglected  through  the  idle  whim  of 
its  impropr'iety  (which  often  only  generates  a false  mod- 
esty or  prudishness),  and  thus  tend  to  a deterioration  of 
the  race  which  is  now  in  fearful  progress  in  the  United 
States. 

Without  a proper  exercise  of  the  muscles  in  man  or 
woman,  all  the  other  portions  of  the  body  must  suffer,  and 
if  so,  why,  througli  an  over  sensitive,  prudish  caution,  must 
woman  be  the  unfortunate  victim?  The  old  Greeks — 
heathen  though  they  were — did  not  neglect  the  development 


AND  PHYSIOLOGY. 


143 


of  the  body  in  either  men  or  women.  And  while  they  most 
thoroughly  disciplined  the  intellectual  powers,  their  ‘‘semi- 
nary of  learning  ^ was  the  gymnasium,  where,  as  prominent 
characteristics,  were  the  running,  wrestling,  and  boxing  exer- 
cises, and  by  them  regarded  as  equally  important  with  intel- 
lectual effort. 

But  though  the  neglect  of  muscular  exercise  is  the  most 
sadly  evident  in  the  female  portion  of  society,  yet  it  is  not 
confined  here.  For  many  of  our  educated  men  are  of  feeble 
physical  culture,  mainly  because  of  the  cultivation  of  the  in- 
tellect at  the  expense  of  the  body.  Most  men  in  the  academ- 
ical and  professional  schools  are  apt  to  regard  study  as  first 
and  foremost,  and  a care  of  the  body  afterwards — if  there  he 
any  time  for  it  I How  many  make  it  a duty — and  a relig- 
ious one  too — to  take  all  the  time  that  can  possibly  be  se- 
cured for  study,  and  leave  the  exercise  as  a thing  desirable 
but  not  essential ! But  we  maintain  that  a system  of  educa- 
tion which  simply  crowds  the  mind  with  discipline,  to  the 
neglect  of  physical  culture,  is  not  only  a defective,  but  a 
monstrously  pernicious  system.  Students  may  bear  the 
cramming  process  through  the  academical,  collegiate,  and 
even  professional  course,  but  sooner  or  later  the  body  will  be 
overpowered.  Nature’s  laws  cannot  be  violated  without  suf- 
fering the  penalty  at  some  time ; and  of  what  service  can  the 
most  cultivated  minds  become,  if  the  body  is  too  feeble  to  use 
their  learning?  Of  what  beauty  is  the  most  brilliant  gem 
without  the  art  of  the  lapidary  to  develop  and  exhibit  its 
splendor  ? 

In  how  few  educational  institutions  in  our  country  is  there 
any  thing  like  a system  of  exercise  suggested,  or  much  more 
required  ? In  how  few  of  them  does  muscular  development 
meet  with  any  thing  but  discouragement  ? 

It  is  true  that  muscular  development  has  for  too  long  a time 
among  us  been  associated  with  the  lower  class  of  people,  as 
prize-fighters,  shoulder-hitters,  bruisers  and  horse-racers,  in 
all  which  cases  it  should  meet  a decided  disapproval.  But  is 

7 


144 


niTc  II  cock’s  anatomy 


this  a natural  tendency  of  physical  development  ? Is  it 
necessary  that  a well-developed  man  must  of  necessity  be  a 
brutal  fighter  ? or  that  a beautiful  horse  must  necessarily  lead 
his  master  to  expose  him  to  cruel  excesses  to  test  his  speed  ? 
If  we  do  adopt  the  principle  that  physical  development  has 
such  an  immoral  tendency,  is  there  any  culture  of  body  or 
mind  that  we  shall  not  be  compelled  to  resign  to  the  great 
tempter,  since  he  can  so  sadly  pervert  every  thing  ? 

Ought  not  then  a gymnasium  or  some  equivalent  means  of 
physical  culture,  to  be  attached  to  all  our  educational  institu- 
tions (female  as  well  as  male),  as  well  as  models,  libraries, 
cabinets,  and  apparatus  ? And  if  so,  why  should  there  not 
be  regular  trainings  of  the  body  required  by  instructors  as  well 
as  mental  exercises  ? And  since  but  a small  portion  of  time^ 
is  required  for  physical  exercise  if  it  be  vigorous,  as  it  will  of 
necessity  be  in  a gymnasium,  why  may  not  a portion  of  school 
duties  each  day  be  a half  hour  or  an  hour  of  exercise  in  the 
gymnasium  morning  and  evening  ? Does  not  every  practical 
teacher  see  that  at  least  this  would  relieve  the  necessity  of  a 
great  many  excuses,  such  as  for  head- ache,’’  feel  sick,” 
unable  to  study  to-day,”  etc. 

There  are,  however,  many  simple  gymnastic  ex- 
ercises which  may  be  indulged  in  by'everybody, 
boys  and  girls,  men  and  women,  without  an  outlay 
of  any  thing  except  a few  dimes,  and  the  use  of  a 
few  yards  of  space  anywhere  on  terra  firma. 

From  a piece  of  inch  pine  board  from  two  to  four 
feet  long  (depending  on  the  size  of  the  person  to 
use  it),  and  three  to  six  inches  wide,  let  an  instru- 
ment be  made  called  the  hack  hoards  as  is  shown 
in  Fig.  153.  With  this  simple  piece  of  apparatus 
grasped  at  each  end,  as  in  Fig.  154,  a great  va- 
riety of  exercises  can  be  invented  by  any  one,  which  will  soon 
set  the  whole  surface  in  perspiration,  and  if  persevered  in 
will,  in  tlie  course  of  several  days,  impart  pliancy  and  strength 
to  the  muscles. 


Fig.  153. 

A 

■1 

i 


AND  PHYSIOLOGY. 


145 


more  vigorous  exercise  can  Fig.  155. 
be  obtained  by  using  what  is 
termed  the  Indian  club/^  or 
scepter/’  one  in  each  hand. 

(See  Fig.  155.)  These  maybe 
made  by  the  commonest  turner 
from  any  sort  of  wood,  and  it 
is  well  that  there  be  several 
pairs  of  them,  differing  in  weight 
and  length,  and  loaded  with 
lead  if  necessary,  adapted  to 
the  age  and  muscular  development  of 
those  using  them.  And  it  is  astonish- 
ing what  great  strength  of  muscle  can 
be  acquired  by  this  means  of  exercise 
continued  through  a few  weeks.  Some 
of  the  different  exercises  which  may  be  performed  with  this 
club  may  be  seen  in  Fig.  156,  p.  146. 

Another  simple  mechanism  for  gaining  physical  exercise, 
called  the  triangle,”  is  seen  in  Figs.  157  and  158.  It  is 


Fig.  158. 


146 


HITCHCOCK’S  ANATOMY 


FlO.  156. 


147 


AND  PHYSIOLOGY. 


Fig.  159. 


made  by  hanging  a bar 
between  the  ends  of  two 
ropes  twisted  together, 
as  in  Fig.  157,  or  from 
two  ropes  hanging  per- 
pendicularly from  the 
ceiling.  This  triangle 
may  be  suspended  from 
the  ceiling  of  any  room, 
or  the  branch  of  a tree, 
and  is  of  great  service 
for  exercise,  since  it 
calls  into  use  not  only 
the  upper,  but  also  the  lower  extremities. 

But  much  more  complete  exercise,  and  that  which  tends  to 
give  symmetry  of  form  to  either  sex,  may  be  obtained  from 


148 


uitcucock’s  anatomy 


Fia.  160. 


AND  PHYSIOLOGY. 


149 


Fia.  161. 


150 


HITCHCOCK’S  ANATOMY 


the  various  appurtenances  of  the  gymnasium.  Here,  hy 
means  of  bars,  ladders,  ropes  and  similar  pieces  of  appara- 
tus are  the  best  arranged  contrivances,  not  only  for  a gen- 
eral exercise  of  the  whole  body,  but  for  developing  the  most 
important  muscles.  A few  pieces  of  this  kind  of  furni- 
ture may  be  seen  in  Figures  159,  160,  and  161.  These 
may  be  fitted  up  in  any  lar^e  and  unfurnished  building, 
since  the  essential  requisites  are  a few  solid  timbers  to 
give  firm  support  to  the  bars  and  ladders,  and  walls  mainly 
to  protect  from  exposure  to  severity  of  weather. 

The  exercise  of  rowing  is  one  which  probably  can  not  be 
surpassed  as  a means  of  exercise,  since  it  not  only  requires  a 
use  of  the  muscles,  but  is  exhilarating  and  recreating  to  the 
spirits ; and  where  circumstances  admit,  whether  as  supple- 
mentary to  or  in  place  of  a gymnasium,  we  would  say  by  all 
means  let  both  boys  and  men,  and  ladies  too,  indulge  in  the 
invigorating  and  healthful  exercise  of  boat  rowing. 


COMPARATIVE  MYOLOGY. 

279.  In  microscopic  structure  the  muscles  of  the  lower 
orders  of  animals  very  closely  resemble  those  of  man,  as  may 
be  seen  in  the  fibrils  of  the  pig.  Fig.  162. 

280.  Tegumentary  Muscle— Abdominal  Mnscles— Mus- 
cles of  Lower  Jaw — Diaphragm. — The  general  structure 
and  relations  of  the  muscles  in  quadrupeds  differ  very  little 
from  those  of  man  save  in  the  extremities.  Nearly  all  quad- 
rupeds have  a set  of  fibers  called  the  Tegumentary  Mus- 
cle, which  is  a thin  layer  of  muscle  lying  just  beneath  the 
skin,  and  which  is  only  rudimentary  in  man.  Its  func- 
tion is  to  contract  and  corrugate  the  skin  in  order  to  remove 
dust,  insects,  or  any  offending  matter,  as  can  bo  seen  in  a 


279.  Wliat  is  said  of  tho  structure  of  muscles  in  all  mammals?  2S0.  Describe  the 
Tetjumentury  Muscle. 


AND  PHYSIOLOGY. 


151 


horse  or  cow  during  the  time  1^2. 

when  flies  irritate  by  biting. 

The  same  muscle  in  the  por- 
cupine and  armadillo  is  made 
use  of  to  roll  themselves  up  in 
a ball.  In  apes  the  foot  and 
hand  are  similar  both  in  mus- 
cular development  and  func- 
tion, but  are  by  no  means 
equal  to  the  hand  of  man. 

The  abdominal  muscles  of  all 
quadrupeds  are  stronger  than 
man’s,  since  from  their  posi- 
tion the  weight  of  the  viscera 
is  thrown  upon  the  muscular 
walls  of  the  abdomen,  and 
not  upon  the  bones  of  the  pelvis,  as  in  him.  In  beasts  of 
prey  the  masseter  and  temporal  muscles  are  more  strongly 
developed  than  in  man,  because  great  strength  is  required 
in  the  jaw  to  secure  the  food  and  fit  it  for  digestion.  In  all 
mammals  a more  or  less  complete  diaphragm  is  found,  though 
it  is  absent  in  nearly  all  the  remaining  vertebrata. 


Muscular  Fibrils  of  the  Pig.  a,  An  ap- 
parently single  fibril,  b c,  Collections  of 
fibrils. 


281.  Muscles  of  Birds — Ossification  of  Tendons.— The 
muscles  of  most  birds  are  remarkable  for  their  deep  red  color 
and  the  density  of  their  structure.  In  herbivorous  ones,  how- 
ever, they  are  of  a paler  color  and  softer  in  texture,  and  hence 
more  palatable  as  articles  of  food.  The  bellies  of  the  muscles 
are  for  the  most  part  situated  on  the  body,  so  that  they  may 
not  encumber  the  limbs  ; and  those  designed  to  move  the  ex- 
tremities are  extended  into  long  tendons,  which,  as  already 
mentioned,  become  ossified  to  a considerable  extent. 


Of  what  use  is  this  muscle  in  the  porcupine  and  armadillo  ? Why  are  the  abdominal 
muscles  of  quadrupeds  proportionally  stronger  than  in  man?  What  is  said  of  the  strength 
of  the  masseter  and  temporal  muscles  of  beasts  of  prey?  What  of  a diaphragm?  2S1. 
What  are  the  muscles  of  birds  remarkable  for?  What  is  said  of  the  tendons  and  bellies 
of  muscles  in  birds? 


1* 


152 


HITCHCOCK’S  anato:my 


282.  Suspensory  Muscle . — In  the  turkey  and  birds  of  like 
character  an  especial  muscle  is  provided  for  the  support  of 
the  crop,  which  «o  often  becomes  heavily  loaded  with  food. 

283.  Muscles  of  Birds’  Feathers  — Their  Use — Their 
Number — Muscles  of  the  Breast. — Birds  are  supplied  with 
tegumentary  muscles  somewhat  after  the  manner  of  quadru- 
peds. The  main  difference  is,  that  in  birds  a few  muscular 
fibers  are  sent  to  each  quill  feather  of  the  body,  by  which  the 
feathers  can  be  violently  shaken  to  dislodge  dirt,  or  they  may 
be  merely  raised  on  end  by  the  same  muscles.  This  property 
is  well  seen  in  common  barn  fowls,  when  they  shake  them- 
selves after  having  lain  in  dry  dirt.  A hen  with  a brood  of 
chickens,  too,  when  disturbed  shows  her  wish  to  protect  her 
young  by  ruffling  up  her  feathers  and  attacking  wdioever  may 
annoy  her.  In  some  birds,  where  there  are  3,000  quill  feath- 
ers, the  number  of  muscles  must  be  at  least  12,000.  No 
muscles  are  found  upon  the  face  of  birds,  but  to  secure  the 
degree  of  motion  to  which  the  head  is  subject,  and  the  flexi- 
bility of  the  neck,  the  muscles  of  this  portion  of  the  body  are 
very  strongly  developed.  The  most  powerful  muscles  of 
birds  are  the  pectoral,  or  those  on  the  breast ; one  end  of 
which  is  attached  to  the  keel  of  the  sternum  and  the  other  to 
the  humerus.  These  muscles  are  three  in  number  on  each 
side,  and  the  largest  one  exceeds  in  weight  all  the  other  mus- 
cles of  the  body. 

284.  Muscles  of  Fishes. — The  muscles  of  fishes  are  char- 
acterized by  their  slight  degree  of  separation  from  one  an- 
other, by  the  absence  of  long  tendons,  and  the  softness  of  their 
fibers.  Their  color  is  generally  white,  or  yellowish  wfflite, 
but  in  microscopic  structure  they  do  not  differ  from  those  of 
the  other  vertebrata.  By  far  the  largest  part  of  the  fleshy 

282.  What  peculiar  muscle  is  found  in  birds  like  the  turkey  ? 283.  What  is  worthy  of 
note  in  the  tegumentary  muscle  of  birds?  In  what  condition  does  a hen  show  the  ac- 
tion of  the  tegumentary  muscles ? What  number  are  there  in  some  birds?  Why  is 
there  need  of  so  few  muscles  on  the  head  of  birds?  Upon  what  portion  of  the  body  are 
there  the  most  muscles?  Give  the  actual  amount  by  weight.  284.  What  is  the  peculiar 
feature  of  the  muscle  of  fishes  ? Give  their  color. 


AND  PHYSIOLOGY. 


153 


mass  of  these  animals  is  made  up  of  the  lateral  muscles  of 
the  bodj  which  extend  from  the  head  to  the  caudal  fin  ; and 
as  each  lateral  muscle  by  its  contraction  bends  the  body  to  its 
own  side,  the  motion  of  the  fish  through  the  water  is  effected 
in  the  same  manner  as  the  oarsman  sculls  his  boat. 

Jig.  163. 


285.  Muscles  and  Locomotive  Organs  of  the  Inverte- 
brates.— Muscles,  both  striated  and  smooth,  voluntary  and 
organic,  abound  in  all  the  invertebrates.  They  are  modified 
in  form  and  position  to  meet  the  wants  of  the  animal  as  wisely 
as  in  the  higher  tribes. 

In  some  of  the  Polypi 
movements  are  made  by 
the  contraction  of  their 
sides,  in  which  no  mus- 
cular fibres  have  been 
discovered,  though  ex- 
existing  in  other  parts 
of  the  animal.  The 
muscles  of  insects  are  either  colorless  or  of  a dirty  yellow. 

286.  A great  variety  of  locomotive  organs  are  found  in  the 
Invertebrates.  The  Echinoderms  have  tentacles,  called  Am- 
bulacra, on  some  of  which  there  are  suckers,  which  enable 
them  to  hold  on  to  substances.  They  have  also  forcep-like 
organs  of  locomotion.  Most  of  the  acephalous  molluscs  move 
by  a highly  developed  foot,  which,  in  the  Cephalopoda,  is  used 
as  a sucker.  The  Cephalopods  have  arms  with  suckers  at- 

What  portion  of  the  hody  is  made  up  of  them  ? 286,  What  are  the  locomotive  organa 
of  Invertebrates? 


Fig.  164. 
ISP 


Insect  Fasciculi  Magnified  Fifty  Diameters. 


154 


II ITC  lie  OCR’s  ANATOMY. 


tached  to  the  cephalic  cartilage.  Annelids  move  by  sub- 
cutaneous muscles,  stings,  and  bristles.  The  Rotatoria  re- 
volve by  a retractile  vibratile  apparatus.  Crustaceans  have 
usually  two  legs  to  each  segment,  and  the  Myriapods  some- 
times four.  Some  of  these  appendages  are  tactile,  some  for 
oars,  and  some  ambulatory.  Spiders  have  four  pairs  of  legs, 
and  insects  three. 

287.  Examples  of  Muscular  Strength —There  are  some 
remarkable  examples  of  muscular  strength  among  the  lower 
animals.  A flea  harnessed  will  draw  from  seventy  to  eighty 
times  its  own  weight,  while  a horse  can  not  draw  more  than 
six  times  his  weight.  The  flea  weighs  less  than  a grain,  and 
will  clear  several  feet  at  a leap.  The  common  dorr  bettle, 
weighing  but  fifteen  grains,  has  been  known  to  heave  a weight 
placed  upon  him  amounting  to  4.769  grains,  equal  to  nearly 
320  times  his  own  weight. 

288.  length  of  Time  the  Muscles  can  be  Employed. 
‘ — The  length  of  time  during  which  some  muscles  can  be  em- 
ployed without  rest  is  also  very  remarkable.  Many  birds  will 
fly  uninterruptedly  for  hundreds  of  miles,  and  it  is  also  said 
that  insects  will  remain  suspended  in  the  air  a whole  sum- 
mer’s day  without  alighting. 

289.  Rate  of  Flight  of  Birds. — Some  birds  fly  sixty 
feet  in  a second ; but  a race-horse  scarcely  ever  exceeds  forty 
feet  in  the  same  time.  A falcon  of  King  Henry  II.  flew  on 
one  day  from  Fontainbleau  to  Malta,  a distance  of  about 
1,000  miles.  The  rice-bird,  which  afterwards  becomes  the 
reed-bird  of  Delaware  Bay  and  the  bobolink  of  New  York,  is 
often  found  below  Philadelphia  with  green  rice  in  its  crop. 
The  same  thing  is  true  of  pigeons  during  the  rice-growing 
season. 


287.  State  the  power  of  a flea  compared  with  a horse.  283.  What  is  wonderful  about 
the  length  of  time  that  some  insects  can  use  their  muscles  without  weariness?  289.  With 
what  speed  can  some  birds  fly?  Give  the  instance  of  King  Henry’s  falcon. 


CHAPTER  THIRD. 


THE  NUTRITIVE  SYSTEM.— SPLANCHNOLOGY,  OR  HISTORY 
OF  THE  DIGESTIVE  ORGANS. 


DEFINITIONS  AND  DESCRIPTIONS. 

290.  Definition  of  Digestive  Organs. — The  Digestive  Or- 
gans are  those  which  receive  the  food  into  the  body  and  effect 
such  changes  in  it  that  the  various  tissues  can  be  formed 
from  it  by  means  of  the  glands.  Of  these  organs  the  princi- 
pal one  is  the  Alimentary  Canal.  This  commences  with  the 
mouth,  and  includes  the  stomach,  with  the  whole  length  of 
tube  known  as  the  intestines.  This  canal,  in  a full-grown 
man  is  about  thirty  feet  in  length,  being  as  a general  rule 
five  times  the  height  of  the  individual,  and  is  lined  through- 
out its  entire  length  by  mucous  membrane. 

291.  The  Mouth;  Salivary  Glands;  the  Tonsils. — The 
Mouth  contains  the  organs  of  mastication  including  the  teeth 
and  tongue,  and  receives  the  saliva,  which  is  secreted  by  three 
pairs  of  glands  named  Parotid,  Submaxillary,  and  Sublingual, 
situated  just  beneath  and  behind  the  lower  jaw.  Besides 
these  three  glands  there  are  many  other  minute  glands  and 
follicles  situated  upon  the  floor  and  backsides  of  the  mouth, 
which  secrete  fluids  that  aid  in  mastication  and  digestion. 
The  Tonsils  are  simply  an  aggregation  of  follicles  situated  in 


290.  What  are  Disrestive  Organs?  Give  the  general  description  of  the  Alimentary 
Canal.  291.  What  does  the  mouth  contain  ? Name  the  three  principal  pairs  of  glands 
and  give  their  location. 


150 


HITCHCOCK’S  anatomy 


Fig.  1G5. 


A View  of  the  Salivary  Glands  in  situ.  1,  The  Parotid  Gland  in  situ  and  extend- 
ing from  the  Zygoma  above  to  the  Angle  of  the  Jaw  below.  2,  The  Duct  of  Steno. 

8,  The  Sub-Maxillary  Gland.  4,  Its  Duct.  5,  Sub-Lingual  Gland. 

the  upper  part  of  the 
fauces  or  throat,  a few 
of  which  are  represent- 
ed in  Fig.  166.  The 
mouth  is  a variable  cav- 
ity having  no  empty 
space  within  it  when 
closed,  and  when  fully 
open,  containing  nearly 
half  a pint. 

292.  The  Pharynx. — 
The  Pharynx  (the  Greek 
name  for  this  portion  of 
the  body)  is  the  next  division  of  the  alimentary  canal.  It  is 
a short  and  somewhat  irreguMr  tubular  cavity,  into  which 
the  mouth  opens  behind,  serving  as  a portion  of  the  canal 


Fig.  166. 


A few  Follicles  from  Human  Tonsil. 


Wliat  are  the  Tonsils?  Aro  tlicro  any  other  glands  in  the  mouth?  292.  Describe  the 
Pharynx. 


AND  PHYSIOLOGY. 


157 


Fig.  167. 

Pendulous  Palate. 


i jNose. 

Base  of  the  Cranium. 

' Tongue. 

Pharynk. 

. Saliv^ary  Glands. 

• Lingual  Bone. 
Larynx. 

Thyroid  Gland. 

Esophagus.  Trachea  or  Windpipe. 

Vertical  Section  of  the  Mouth  and  Throat. 


from  the  mouth  to  the  stomach,  its  lower  limit  being  nearly 
opposite  to  the  Pomum  Adami  (Adam’s  apple)  in  front,  and 
the  fifth  cervical  vertebra  behind.  It  also  communicates  with 
both  ears,  with  the  nostrils  and  lungs,  by  passages  which  open 
directly  into  it.  The  communication  between  this  cavity  and 
the  mouth  may  be  entirely  cut  off  by  means  of  a movable 
muscular  curtain  called  the  soft  or  pendulous  palate,  which  is 
of  great  service  in  the  act  of  swallowing.  This  portion  of  the 
alimentary  canal  is  made  up  of  muscular  fibers  which  run  in 
two  directions,  so  as  to  cross  each  other  at  a large  angle,  in 
order  to  give  the  most  perfect  compression  upon  the  food  as 
it  passes  through  it.  And  in  its  lining  (mucous)  membrane 
are  found  a great  number  of  follicles  or  sac-like  bodies  of 
microscopic  size  called  Pharyngeal  Glands. 

293.  Esophagus. — The  Pharynx  terminates  in  the  Eso- 
phagus (meaning  the  passage  for  conveying  the  food).  This 


What  cavities  does  it  communicate  with?  What  is  said  of  its  muscular  coat?  293. 
What  is  the  Esophagus  ? 


ir  ITCH  cock’s  anatomy 


ir.8 


FiO.  1G8. 


Glands  of  Esophagus  Magnified  fifteen  Times. 

is  a long  and  narrow  tube,  made  up  of  two  muscular  coats, 
which  terminates  in  the  stomach  by  the  cardiac  orifice.  It  is 
smaller  in  size  than  the  Pharynx,  and  contains  a great  num- 
ber of  minute  glands,  (see  Fig.  168),  which  secrete  an  oily 
fluid  when  the  food  is  passing  through  it. 

294.  Stomach,  its  Coats,  its  Size,  its  muscular  Coat, 

Fig.  169. 


Section  of  Human  Stomach.  1,  Esophagus.  2,  Cardiac  Orifice.  3,  4,  5,  6,  Greater 
and  Lesser  Curves  of  the  Stomach.  7,  Dilatation,  or  rudiment  of  a Second  Stomach. 
8,  Fold*  of  the  Mucous  Membrane.  9,  Pyloric  Orifloo.  10,  11,  and  14,  Duodenum. 
12,  Duct  of  Pancreas  and  Liver.  15,  Jejunum. 


AND  PHYSIOLOGY. 


159 


Gastric  Follicles. — The  Stomach  is  the  largest  expansion  of 
the  alimentary  canal,  situated  in  the  upper  portion  of  the 
left  side  of  the  abdomen,  immediately  beneath  the  diaphragm, 
inclining  obliquely  downwards  from  the  left  to  the  right.  Its 
walls  are  made  up  of  three  coats : an  outer  or  serous,  a middle 
or  muscular,  and  an  inner  or  mucous.  Its  normal  or  average 
size  will  allow  it  to  contain  about  a solid  quart,  but  in  gor- 
mandizers, and  wine  and  beer  drinkers,  it  is  dilated  to  three 
or  four  times  that  size.  In  the  middle  or  muscular  coat  (Fig. 
170)  the  fibers  run  at  right  angles  to  each  other,  in  order  that 


Fig.  110. 


A Front  View  of  the  Stomach,  distended  by  flatus,  with  the  Peritoneal  Coat  turned 
off.  1,  Anterior  Face  of  the  Esophagus.  2,  The  Cul-de-Sac,  or  greater  Extremity. 
8,  The  lesser  or  Pyloric  Extremity.  4,  The  Duodenum.  5,  5,  A portion  of  the  Peri- 
toneal Coat  turned  back.  6,  A i>ortion  of  the  Longitudinal  Fibers  of  the  Muscular  Coat. 
7,  The  Circular  Fibers  of  the  Muscular  Coat.  8,  The  Oblique  Muscular  Fibers,  or 
Muscle  of  Gavard.  9,  A portion  of  the  Muscular  Coat  of  the  Duodenum,  where  its  Pe- 
ritoneal Coat  has  been  removed. 

they  may  contract  in  the  most  efficient  manner  upon  the  con- 
tents of  the  stomach  for  the  purpose  of  digestion,  and  forcing 
the  contents  onwards  into  the  Duodenum.  They  also  assist 
in  forcing  the  contents  of  the  stomach  backward  in  vomiting. 
In  the  inner  or  mucous  lining  are  situated  an  immense  num- 

294.  "Where  is  the  Stomach  situated?  What  is  its  normal  size?  How  many  coats  has 
it  and  what  are  they?  Of  what  service  is  the  muscular  coat?  What  glands  are  con- 
tained in  the  mucous  membrane  of  the  stomach  ? 


160 


HITCHCOCK’S  ANATOMY 


ber  of  tubular  glands  which  open  directly  into  the  stomach. 
They  are  cup-shaped  cavities  about  the  asVexth  of  an  inch  in 
diameter,  and  jVth  in  length,  from  the  bottom  of  which  pro- 
ject two  or  more  parallel  tubes,  ending  in  a closed  termina- 
tion in  the  tissue  beneath.  These  compose  tlie  greater  por- 
Fw-  111-  F:g.  172. 


Diagram  of  tbo  Stomach  and  Intestines.  1,  Stomach. 
2,  Esophagus.  8 and  4,  Stomacli.  5 and  G,  Duode- 
num. 7,  Jejunum.  8,  Ileum.  9,  Csucum.  10,  Vor- 
inlforin  Appendix.  11,  12,  18, 14,  Colon.  15,  Rectum. 


Stomacli,  magnified  forty-five  dia" 
meters.  1,  A Gastric  Gland,  from 
the  middle  of  tlie  Stomach.  2,  An- 
other, of  more  com[)lcx  structure, 
and  appearing  to  contain  Mucus 
— from  the  neighborhood  of  the 
Pylorus. 

tion  of  the  mucous  mem- 
brane, and  are  for  the 
purpose  of  secreting  the 
gastric  juice,  and  prob- 
ably the  Pepsin  also.  In 
addition  to  these  glands, 
a large  number  of  the 
mouths  of  veins  open 
into  the  stomach,  which 
act  the  part  of  absorbent 
vessels  to  remove  the 
water,  whether  pure  or 
mixed  with  other  sub- 
stances. 

295.  Duodenum. — 
The  first  division  of  the 
Intestines  is  the  Duo- 


AND  PHYSIOLOGY. 


161 


denuni;  because  in  length  it  is  equal  to  the  breadth  of  twelve 
fingers.  It  commences  with  the  pyloric  orifice  on  the  right 
extremity  of  the  stomach,  and  runs  slightly  backwards  and 
upwards  until  it  terminates  in  the  Jejunum.  It  is  often 
called  the  second  stomach,  because  a certain  part  of  digestion 
takes  place  here,  and  the  food  passes  slowly  and  receives  no 
less  than  three  different  secretions  : one  from  the  Liver,  an- 
other from  the  Pancreas,  and  the  third  from  the  Mucous 
membrane  of  the  intestine  itself. 

296.  Jejunum. — Next  below  the  Duodenum  is  the  Jeju- 
num, meaning  ‘‘empty,’’  since  it  is  always  found  in  this  con- 
dition after  death.  This,  like  the  other  divisions  of  the  intes- 
tine, has  three  coats,  and  is  of  a slightly  pinkish  color,  be- 
cause here  the  mucous  membrane  is  thicker  than  in  any  other 
of  the  intestines.  Us. 


297.  Ileum. — The  Ileum 


(from  the  Greek  signifying 
to  twist)  is  the  third  division 
of  the  Intestines,  and  is  about 
fifteen  feet  in  length.  It  is 
the  smallest  Intestine,  and  has 
a darker  color  than  either  of 
those  already  mentioned,  and 
is  exceedingly  tortuous  in  its 
course. 


298.  Caecum. — The  fourth 
division  of  the  Intestine  is 
the  Caecum.  This  is  a shut 
sac  much  larger  than  the 
small  Intestine,  and  of  a 


The  Caecum  and  its  Appendix.  1,  Cae- 
cum. 2,  Colon.  3,  Ileum.  4,  Entrance 
from  Ileum  to  Colon.  5,  llio-Caecal  Valve. 
6,  T,  9,  Parts  of  the  Appendix  Caeci. 


What  do  they  secrete  ? What  vessels  open  into  the  stomach,  and  of  what  service  are 
they?  295.  What  is  the  Duodenum ? Give  its  general  course.  Why  is  it  sometimes 
called  the  second  stomach?  What  fluids  are  poured  into  it?  296.  What  is  the  name 
Jejunum  derived  from?  What  is  its  color?  297.  How  long  is  the  Ileum?  What  is 
said  of  its  shape?  298.  Name  the  fourth  divison  of  the  intestines.  Describe  it. 


1G2 


11  1 T C II  G O 0 K ’ S ANATOMY 


grayish  blue  color,  and  not  exceeding  three  inches  in  length. 
The  entrance  of  the  Ilium  into  the  Caecum  is  effected  by  a 
valvular  arrangement  Avhich  allows  the  food  to  pass  into  the 
Caecum,  but  never  in  the  opposite  direction.  It  is  situated  at 
the  right  Innominatum  in  the  lower  part  of  the  abdomen,  and 
its  lowest  portion  has  a worm-shaped  process  attached  to  it, 
which  is  only  rudimentary,  and  consequently  of  no  great 
service  to  man,  but  largely  developed  and  of  great  service  in 
some  of  the  lower  animals,  and  especially  in  the  herbivorous 
ones. 

299.  Colon. — The  Colon  (from  the  Greek  signifying  ‘Go 
prohibit,’’  since  the  food  passes  very  slowly  through  this  part 
of  the  canal),  commences  at  the  Caecum  on  the  right  side  of 
the  abdomen,  and  in  the  first  part  of  its  course  passes  in  an 
upward  direction,  and  is  called  the  ascending  Colon.  When 
it  reaches  the  lower  edge  of  the  liver,  it  crosses  horizontally 
to  the  extreme  left  edge  of  the  body,  constituting  the  trans- 
verse Colon.  After  this  it  descends,  and  joins  the  Rectum, 
forming  the  descending  Colon.  Its  length  is  from  five  to 
eight  feet. 

800.  Rectum. — The  Rectum  completes  the  divisions  of  the 
Intestines.  It  is  nearly  straight  in  its  course,  of  a larger 
size  than  any  other  division  of  the  canal,  except  the  stomach, 
and  from  six  to  eight  inches  in  length.  Its  name  is  derived 
from  the  straight  direction  which  it  assumes. 

301.  Division  of  the  Intestines  into  small  and  large. — 
The  last  three  divisions  have  a much  larger  diameter  than 
the  first  three,  and  are  called  on  that  account  the  large  Intes- 
tine, and  the  Duodenum,  Jejunum  and  Ilium,  the  small  In- 
testine. The  latter  seems  to  be  the  portion  necessary  for 
preparing  the  food  to  enter  the  Lacteals,  while  the  large  In- 
testines act  mainly  as  a receptacle  for  the  waste  portion. 

Where  Is  its  location  in  the  body  ? What  curious  appendage  is  attached  to  it?  299. 
What  arc  the  three  divisions  of  the  Colon?  How  lon^  is  it?  800.  What  does  the  Colon 
terminate  in?  Ifow  lonj'  is  tlio  Kectuui?  801.  Dcliao  the  largo  and  tho  small  Intestine, 
and  give  their  probablo  uses. 


AITD  PHYSIOLOGY. 


163 


Fig.  lU. 

Liyer.  Pylorus.  Gullet.  Pancreas 
\ \ ' ' 


Gall-Bladder. 


Large  Intestine. 


Caecum., 

Appendix  of  the 
Caecum. 


Stomach. 


Spleen. 


Colon. 


Small  Intestine. 
• Colon. 


Small  Intestine. 


Pectum. 


Digestive  Apparatus  in  Man. 

302.  Structure  of  Intestines,  Intestinal  Glands. — Like 
the  Stomach,  the  Intestines  are  formed  by  three  membranes. 
Also  in  the  inner  or  mucous  membrane  are  situated  an  im- 
mense number  of  microscopic  glands,  so  that  a French  teacher 
speaks  of  them  existing  ‘^as  numerous  as  the  stars  in  the 
starry  heavens.’’  They  are  distinguished  as  Duodenal  Glands, 
Brunner’s  Glands,  Solitary  Glands,  Peyer’s  Patches,  and 
Follicles  of  Lieberkiihn.  (Fig.  175,  p.  164.)  They  are 
most  abundant  along  the  course  of  the  Ileum  and  they  seem 
to  be  especially  affected  in  Typhoid  Fever,  although  no  cer- 
tain use  for  them  in  health  has  as  yet  been  discovered.  The 


302.  What  is  the  stnicture  of  the  Alimentary  Tube .?  What  is  said  of  the  Glands  found 
in  its  mucous  lining  ? State  their  names. 


164 


II  I T C TI  C O C K ’ S A X A T O ]\r  Y 


Follicles  of  Licbcrkiilin 
arc  found  only  in  the 
large  intestine.  T li  o 
Mucous  membrane  of 
this  part  of  the  canal, 
is  not  smooth  and  con- 
tinuous with  the  serous 
or  outer  layer,  but  is 
doubled  upon  itself  in  a 
great  number  of  folds, 
in  order  that  the  surface 
containing  these  glands 
may  be  the  largest  that 
is  possible,  so  that  the 
contents  of  the  Intestine 
may  receive  a large 
supply  from  these  secretions.  Minute  Villi  or  hair- like  pro- 
jections are  also  found  in  great  abundance  upon  this  mem- 


A Portion  of  the  Ilium  highly  magnified,  show- 
ing Peyer's  Patches  and  the  Villi. 


Fig.  176. 


Fig.  177. 


A Portion  of  one  of  Brunner’s  Glands.  A View  of  a Longitudinal  Section  of  the 

Jejunum,  showing  the  Villi  as  seen  under 
the  Microscope.  1, 1,  The  Terminal  Orifices  of  the  Villi.  2,  2,  The 
Internal  Coats  of  the  Intestine.  3,  The  Peritoneal  Coat. 


How  is  the  Mucous  membrane  arranged  through  the  canal,  and  what  is  the  design  of 
such  an  arrangement? 


AKD  PHYSIOLOGY. 


165 


brane,  in  order  to  increase  the  amount  of  its  secretory  surface. 
It  is  the  presence  of  villi  that  gives  to  some  parts  of  the  mu- 
cous membrane  a velvet-like  appearance,  and  in  these  villi 
are  found  the  commencement  of  the  lacteals,  one  lacteal 
usually  being  found  in  each  villus. 

303.  Glands  attached  to  the  Intestines. — Connected 
with  the  Alimentary  Canal  are  several  large  glands,  a few  of 
which  have  already  been  described.  They  are  soft  solids,  of 
various  forms  and  sizes,  and  are  composed  of  lobules  or  small 
divisions,  each  one  of  which  is  supplied  with  an  artery,  vein, 
and  duct.  Each  of  these  ducts  communicates  with  the  prin- 
cipal duct  or  outlet,  which  conveys  away  the  product  sepa- 
rated from  the  blood  by  the  whole  gland.  In  microscopic 
structure,  a gland  is  made  up  of  very  minute  cells,  which 
seem  to  have  the  power  of  secreting  or  separating  from  the 
blood  the  particular  substance  which  it  is  the  function  of  the 
gland  to  eliminate. 

304.  The  liver,  Gall-Bladder, — First  in  importance  of 
this  class  is  the  Liver.  (Fig.  178,  p.  166.)  This,  except- 
ing the  brain,  is  the  largest  organ  in  the  body,  and  is  situated 
on  the  right  side  of  the  abdomen,  corresponding  to  the  stom- 
ach on  the  left,  and  is  of  a reddish  yellow  color.  The  average 
weight  of  it  is  four  pounds,  measuring  twelve  inches  in  its 
longest  diameter,  and  it  is  divided  into  five  lobes  or  great  divis- 
ions, and  these  are  entirely  composed  of  minute  bodies  or 
lobules,  (Fig.  179,  p.  166),  w^hich  are  about  the  size  of  millet 
seeds,  each  one  containing  an  artery,  a vein,  and  a plexus,  or 
net- work  of  ducts  for  conveying  away  the  bile.  These  differ- 
ent plexuses  unite  with  each  other  and  form  two  hepatic  ducts 
which  discharge  the  bile  into  the  Gall  Cyst  or  bladder.  (Fig. 
180,  p.  167.)  This  is  a pear-shaped  sac,  containing  from 
one  to  two  ounces,  of  a greenish  yellow  color,  situated  under 

Describe  the  Villi.  303.  What  is  said  of  the  lar^e  glands  connected  with  the  organs  of 
digestion?  State  the  structure  of  a gland.  304.  What  is  the  relative  size  of  the  Liver? 
Where  is  it  located  ? State  its  color  and  weight.  Give  its  minute  structure.  What  is 
the  Gall  Cyst  or  Bladder  ? What  is  the  duct  that  carries  the  Bile  to  the  Gall  Cyst,  and 
the  one  that  empties  the  Gall  Cyst  into  the  Duodenum  ? 


IGG 


HITCHCOCK’S  ANATOMY 


Fig.  178. 


The  Inferior  or  Concave  Surface  of  the  Liver,  showing  its  Subdivisions  into  Lobes. 

I,  Center  of  the  Eight  Lobe.  2,  Center  of  the  Left  Lobe.  3,  Its  Anterior,  Inferior,  or 
Thin  Margin.  4,  Its  Posterior,  Thick  or  Diaphragmatic  Portion.  6,  The  Eight  Extrem- 
ity. 6,  The  Left  Extremity.  7,  The  Notch  on  the  Anterior  Margin.  8,  The  Umbilical 
or  Longitudinal  Fissure.  0,  The  Eound  Ligament  or  remains  of  the  Umbilical  Vein. 
10,  The  Portion  of  the  Suspensory  Ligament  in  connection  with  the  Eound  Ligament. 

II,  Pons  Ilepatis,  or  Band  of  Liver  across  tlio  Umbilical  Fissure.  12,  Posterior  End  of 
Longitudinal  Fissure.  13,  14,  Attachment  of  the  Obliterated  Ductus  Venosus  to  the 
Ascending  Vena  Cava.  15,  Transverse  Fissure.  IG,  Section  of  the  Hepatic  Duct.  17, 
Hepatic  Artery.  IS,  Its  Branches.  19,  Vena  Portarum.  20,  Its  Sinus,  or  Division  into 
Eight  and  Left  Branches.  21,  Fibrous  remains  of  the  Ductus  Venosus.  22,  Gall-Blad- 
der. 23,  Its  Neck.  24,  Lobulus  Quartus.  25,  Lobulus  Spigelii.  26,  Lobulus  Caudatus. 
27,  Inferior  Vena  Cava.  28,  Curvature  of  Liver  to  fit  the  Ascending  Colon.  29,  De- 
I)ression  to  fit  the  Eight  Kidney.  30,  Upper  portion  of  its  Eight  Concave  Surface  over 
the  Eenal  Capsule.  31,  Portion  of  Liver  uncovered  by  the  Peritoneum.  32,  Inferior 
Edge  of  the  Coronary  Ligament  in  the  Liver.  33,  Depression  made  by  the  Vertebral 
Column. 


Fig.  179. 


the  right  side  of  the 
liver,  and  has  a 
small  vessel  called 
the  Bile  Duct,  which 
enters  the  Duode- 
num obliquely  about 
three  inches  from 
the  stomach. 

305.  Pancreas. — 
The  Pancreas  (^^all 
flesh,’’  because  there 
is  no  fat  ever  found 
in  it)  is  another 


Transverso  Boction  of  a Lobule  of  the  Humau  Liver. 


AND  PHYSIOLOGY 


167 


Fia.  180. 


A View  of  the  Gall-Bladder  distended  with  Air,  and  with  its  Vessels  Injected. 

1,  Cystic  Artery.  2,  The  Branches  of  it  which  supply  the  Peritoneal  Coat  of  the 
Liver.  8,  The  Branch  of  the  Hepatic  Artery  which  goes  to  the  Gall-Bladder.  4, 
The  Lymphatics  of  the  Gall-Bladder. 

gland,  lying  directly  behind  the  stomach.  It  is  about  six 
inches  in  length,  the  right  end  of  it  being  somewhat  larger 
than  the  left  extremity,  and  hence  called  the  head.  To  the 
naked  eye  the  lobular  structure  is  apparent : but  each  lobule 
is  itself  made  up  of  much  smaller  lobules.  The  duct  of  the 
Pancreas  conveys  the  milk-like  secretion  of  this  gland,  to 
nearly  the  same  point  on  the  Duodenum  as  the  Hepatic  Duct, 
where  they  both  enter  that  tube  in  a slanting  manner,  so  that 
by  the  valvular  arrangement  the  contents  of  the  intestine  can 
not  be  forced  backwards  into  the  Biliary  or  Pancreatic  duct. 


Fia.  181. 


3 


An  Anterior  View  of  the  Pancreas,  Spleen  and  Duodenum,  with  their  Blood-Ves- 
sels Injected.  1,  The  Spleen.  2,  Its  Diaphragmatic  Extremity.  3,  Its  Inferior 
Portion.  4,  The  Fissure  for  its  Vessels.  5,  The  Pancreas.  6,  Its  Head,  or  the 
Lesser  Pancreas.  7,  Duodenum.  8,  Coronary  Arteries  of  the  Stomach.  9,  The 
Hepatic  Artery.  10,  The  Splenic  Artery.  11,  The  Splenic  Vein. 

805.  Describe  the  Pancreas.  What  is  its  structure?  Where  does  its  duct  empty,  and 
what  mechanical  structure  in  it  makes  it  remarkable  ? 

S 


m 


HITCHCOCK’S  ANATOMY 


Fig.  182.  306.  Pcriton  cum. — 

The  Peritoneum,  ‘‘cov- 
ering about/ ^ or  exter- 
nal coat  of  the  intes- 
tines is  not  a little  pe- 
culiar in  its  conforma- 
tion. This,  like  all 
serous  membranes,  first 
completely  invests  the 
organs  and  then  is  re- 
flected from  them  so  as 
to  make  a lining  for  the 
whole  cavity.  Hence 
the  cavity  of  the  ab- 
domen, although  a per- 
fectly shut  sac,  is  of 
very  irregular  outline. 
That  it  is  a shut  sac 
may  be  seen  from  the 
fact  that  in  dropsy  of 
the  abdomen — the  fluid 
has  no  means  of  escape 
except  by  absorption,  or 
puncture  from  the  out- 
side. In  the  disease 
commonly  known  as  in- 
flammation of  the  bow- 
els, this  membrane  is  the  principal  seat  of  the  difiiculty,  and 
the  inflammation  of  this  as  well  as  of  all  other  serous  mem- 
branes, is  attended  with  acute  pain,  and  the  progress  of  the 
disease,  for  better  or  worse,  very  rapid. 


Eeflexions  of  the  I’eritoneum.  D.  Diaphragm. 
iS.  Stomach.  C.  Colon.^  D.  Duodenum.  /*.  Pan- 
creas. Z Small  Intestine,  i?.  Ilectum.  Blad- 
der. The  numbers  indicate  the  course  of  the 
Peritoneum. 


307.  Tlie  Mesentery  and  tiic  Omentum. — These  are  folds 
of  the  Peritoneum,  attached  to  different  parts  of  the  abdomen 
and  its  viscera,  which  servo  to  retain  some  of  the  organs  in- 


300.  What  is  tlio  Peritoneum  ? Is  tlie  cavity  of  the  abdomen  of  a regular  outline? 
What  is  the  principal  seat  of  dlsoaso  in  i iflammation  of  the  bowels?  307.  What  is  the 
Afcsentcry  and  the  Omentum  ? Wh  it  is  it  thickly  packed  with? 


AND  PHYSIOLOGY. 


1G9 


their  positions,  and  also,  from  the  amount  of  fat  contained  in 
them,  to  protect  the  intestines  from  cold  and  mechanical 
violence,  and  to  furnish  a soft  surface  for  them  to  glide  over 
in  their  various  movements.  In  a lateral  view  of  the  abdo- 
men, Fig.  182,  some  of  the  parts  of  the  Omentum  and  Me- 
sentery may  be  seen.  At  4 is  seen  what  is  known  as  the 
lesser  Omentum,  connecting  the  Liver  and  the  Stomach.  At 
5 and  6 are  seen  the  folds  which  constitute  the  greater 
Omentum.  At  10  is  found  the  Mesentery,  which  encircles 
the  small  intestines.  This  is  a broad  fold  of  the  Peritoneum 
connected  to  the  middle  of  the  cylinder  of  the  Jejunum  and 
Ileum  through  their  whole  length,  and  is  attached  to  the 
posterior  wall  of  the  abdomen.  Within  the  layers  of  the  Me- 
sentery are  found  from  130  to  150  bodies  of  almond  shape 
and  size,  known  as  the  Mesenteric  Glands.  Through  these 
the  Lacteals  pass  on  their  way  to  form  the  Thoracic  Duct. 

808.  lacteals. — The  Lacteals  are  minute  vessels,  which 
commence  with  the  inner  or  mucous  coat  of  the  intestines, 


Fig.  183. 

Aorta.  Thoracic  Canal.  Lymphatic  Glands. 


Intestine. 


( Radicles  of  th 
< Chyliferous 
I Vessels. 


of  the 


Lacteals.  Mesenteiy, 

Chyliferous  Vessels. 


What  small  bodies  are  found  in  it,  and  what  is  the  use  of  the  Mesentery  ? 


170 


HITCHCOCK’S  A X A T O H Y 


Fig.  184. 


and  terminate  in  the  Thoracic 
Duct.  These  at  their  com- 
mencement arc  a))out  the 
same  in  anatomy  >vith  the 
radicles  or  small  veins,  and 
at  this  point  act  the  part  of 
absorbents.  Soon  after  they 
have  left  the  Intestines,  sev- 
eral of  them  unite  into  one 
and  pass  through  small  bodies 
of  about  the  size  of  peas, 
called  the  Mesenteric  Glands. 
As  they  emerge  from  these 
glands,  they  are  fewer  in 
number  but  larger  in  size, 
until  they  all  unite  into  one 
tube  called  the  Thoracic  Duct, 
a little  larger  than  a goose 
quill,  at  about  the  point  of 
the  last  Dorsal  Vertebra. 
This  vessel  passes  immedi- 
ately upwards,  lying  closely 
upon  the  Spinal  Column, 
sometimes  separating  into  two 
smaller  tubes  for  a few^  inches, 


A View  of  the  Course  and  Termination  of  the  Thoracic  Duct.  1,  Arch  of  the  Aorta. 

Thoracic  Aorta.  3,  Abdominal  Aorta.  4,  Arteria  Innominata.  5,  Left  Carotid.  6, 
Left  Sub-Clavian.  7,  Superior  Cava.  8,  The  two  Venae  Inuominatae.  9,  The  Internal 
Jugular  and  Sub-Clavian  Vein  at  each  side.  10,  The  Vena  Azygos.  11,  The  Termina- 
tion of  the  Vena  Ilerni-Azygos  in  the  Vena  Azygos.  12,  The  Receptaculum  Chyli ; sev- 
eral Lymphatic  Trunks  are  seen  opening  into  it.  13,  The  Thoracic  Duct  dividing,  op- 
posite the  Middle  Dorsal  Vertebra,  into  two  branches,  which  soon  re-unite;  the  course 
of  the  Duct  behind  the  Arch  of  the  Aorta  and  Left  Sub-Clavian  Aorta  is  shown  by  a 
Dotted  Line.  14,  The  Duct  making  its  turn  at  the  Root  of  the  Neck  and  receiving  se\'- 
eral  Lymphatic  Trunks  previous  to  terminating  in  the  Posterior  Angle  of  the  Junction 
of  the  Internal  Jugular  and  Sub-Clavian  Veins.  15,  The  Termination  of  the  Trunk  of 
the  Lymphatics  of  the  Upper  Extremity. 


30S.  Where  do  the  Lacteals  begin,  and  where  do  they  terminate?  What  do  they  re- 
Kcmble,  and  what  do  they  pass  through  ? State  the  size  of  the  Thoracic  Duct,  its  course 
and  termination. 


AND  PHYSIOLOGY. 


in 

until  it  reaches  a point  as  high  as  the  clavicle,  where  it 
gradually  curves  forward,  and  joins  itself  to  the  left  sub- 
clavian vein.  The  Lacteals  and  Thoracic  Duct  are  all  made 
up  of  three  coats  and  present  a silvery  white  appearance 
from  the  color  of  the  fluid  they  contain.  Their  function  is 
to  convey  the  Chyle  or  nutrient  portion  of  the  food  into  the 
blood. 

309.  Kidneys. — The  Kidneys  are  two  in  number,  situated 
upon  the  side  of  the  lumbar  vertebrae,  and  are  generally  en- 
closed in  a large  amount  of  fat.  Their  average  size  is  be- 
tween four  and  five  inches  in  length,  two  and  a half  inches  in 
breadth,  and  one  in  thickness.  Their  color  is  of  a reddish 
yellow,  and  form  decidedly  oval,  with  a depression  in  one  of 
the  sides.  Upon  its  upper  extremity  is  a small  body,  called 
the  Renal  Capsule,  and  the  whole  organ  is  abundantly  sup- 
plied with  blood.  The  design  of  it  seems  to  be  the  removal 

Fig.  186. 


a 

I 

c 

d 


Diagram  of  the  Urinary  Apparatus. 

The  Kidneys,  The  Ureter,  o,  The 
Bladder,  tf,  Canal  of  the  Urethra. 


A Section  of  the  Right  Kidney  surmounted  by  the  Renal  Capsule.  1,  Supra-Renal 
Capsule.  2,  Cortical  Portion.  3,  Medullary  or  Tubular.  4,  Two  of  the  Calices 
receiving  the  Apex  of  their  corresponding  Cones.  5,  The  Infundibula.  6,  The 
Pelvis.  7,  The  Ureter. 


Fig.  185. 


What  vein  does  it  empty  into?  What  fluid  docs  it  carry?  309.  State  the  leading 
features  of  the  Kidneys.  What  is  found  upon  its  upper  edge  ? 


172 


HITCHCOCK’S  ANATOMY 


of  the  waste  Nitrogen  of  the  system,  and  many  salts,  espe- 
cially the  Phosphates,  which  can  be  eliminated  by  no  other 
organ.  The  secretion  of  the  kidneys  is  the  urine,  upon 
the  regular  secretion  of  which  the  health  of  the  system  greatly 
depends. 


FUNCTIONS  OF  THE  DIGESTIVE  ORGANS. 

310.  Mastication;  Use  of  the  Tongue;  Use  of  the  Saliva. 
Amount  of  Saliva. — The  first  process  through  which  the  food 
must  pass  is  Mastication,  or  reducing  it  to  a pulp  by  means  of 
the  teeth  and  admixture  of  the  saliva.  The  service  of  the  tongue 
is  to  keep  the  food  between  the  teeth  and  to  place  it  in  such  a 
position  that  it  will  readily  receive  the  saliva.  The  saliva  is 
of  use  to  moisten  the  food,  since  the  gastric  fluid  will  much 
more  readily  dissolve  it  than  if  dry  or  solid.  It  aids  articu- 
lation and  the  sense  of  taste  by  keeping  the  lining  of  the 
mouth  in  a moist  and  pliant  state.  It  also  is  of  use  to  cleanse 
the  mucous  membrane,  and  by  its  moisture  to  quench  or  pre- 
vent thirst.  Air  is  also  carried  by  it  into  the  stomach  to  aid 
the  process  of  digestion.  But  the  most  important  use  of  this 
fluid  is  the  conversion  of  starch  into  sugar.  This  property 
depends  mainly  upon  a peculiar  organic  active  substance  con- 
tained in  it  called  Ptyalin,  and  is  most  active  when  in  a state 
of  incipient  decomposition.  The  saliva  secreted  daily  varies, 
according  to  diflerent  authorities,  from  about  three  pounds  to 
six  pounds  and  a half,  and  is  alkaline  in  its  character.  Acid, 
aromatic,  and  pungent  substances  increase  the  amount  of  the 
secretion  very  much. 

311.  Dcgliilition.  A part  of  the  Process  involuntary. 
— After  mastication,  the  next  process  is  that  of  swallow- 
ing, or  deglutition.  The  first  step  is  to  place  the  bolus, 
or  mouthful,  upon  the  back  part  of  the  tongue,  when  by 


or  what  fjroat  iiso  aro  tho  Kidneys?  810.  Describe  tlio  process  of  Mastication.  Of 
wliat  use  is  tlie  Saliva  ? How  inucli  Is  secreted  every  day  ? What  increases  its  amount? 
811.  Describe  tho  process  of  swallowing. 


AND  PHYSIOLOGY, 


173 


the  muscles  of  the  tongue  and  fauces  it  is  forced  into  the 
Pharynx.  As  soon  as  it  fairly  enters  this  passage,  the  mus- 
cles by  an  involuntary  movement  seize  it,  and  force  it  rap- 
idly past  the  opening  into  the  lungs,  and  at  the  same 
moment  the  epiglottis  is  forced  down  upon  the  larynx,  to 
prevent  its  entrance  into  the  trachea.  This  part  of  the  pro- 
cess is  involuntary,  from  the  necessity  of  keeping  the  passage 
to  the  lungs  open  as  much  as  possible,  in  order  to  admit  air, 
and  also  from  the  great  danger  of  introducing  any  other  sub- 
stance. And  so  perfectly  carried  on  is  this  function  that  it  is 
seldom — compared  with  the  frequency  of  deglutition — that 
even  a fluid  escapes  the  vigilance  of  this  sentinel. 

812.  Passage  of  the  Food  through  the  Esophagus, — The 
food  passes  slowly  through  the  Esophagus  into  the  stomach, 
it  being  forced  along  by  the  contraction  of  the  muscular 
fibers,  aided  by  the  oily  secretion  of  the  Esophageal  glands. 

813.  Gastric  Digestion. — As  soon  as  the  food  I’eaches  the 
stomach,  the  most  important  part  of  the  process  of  digestion 
commences,  all  the  previous  steps  being  preliminary.  When- 
ever any  solid  substance  comes  in  contact  with  the  inner  or 
mucous  membrane  of  the  stomach,  it  excites  the  gastric  glands 
to  pour  out  in  abundant  quantity  the  Gastric  fluid. 

314.  Gastric  Fluid — its  Amount— Pepsin. — This  fluid  is 
a transparent  liquid  of  a little  greater  consistency  than  water, 
and  of  a perceptibly  acid  taste.  It  possesses  the  property  of 
coagulating  albumen,  and  of  separating  the  whey  or  serum 
from  the  milk  in  a very  short  time,  and  is  secreted  at  the  rate 
of  seventy  ounces  per  day.  This  property,  however,  is  owing 
to  a peculiar  organic  compound  called  Pepsin,  which  acts  after 
the  manner  of  a ferment  at  the  normal  temperature  of  the 
human  body.  The  Gastric  fluid  also  possesses  antiseptic 


What  part  of  the  process  is  under,  and  what  part  is  not  under  the  control  of  the  will? 
812.  How  is  the  food  carried  through  the  Esophagus?  313.  Where  does  the  most  im- 
portant part  of  digestion  take  place  ? What  effect  has  any  solid  substance  upon  the  Gas- 
tric Glands  of  the  Stomach  ? 814.  What  are  the  properties  of  the  Gastric  Fluid?  How 
much  is  secreted  daily  ? What  effect  has  it  on  the  decay  of  substances  ? 


174 


HITCHCOCK’S  ANATOMY 


properties,  or  the  power  of  preventing  decay  or  putrefaction 
for  a long  time.  These  three  properties,  the  acid,  fermenta- 
tive, and  antiseptic,  are  of  service  in  the  following  manner. 
The  acid  assists  in  the  solution  of  the  different  materials  in 
the  stomach.  The  Pepsin,  which  constitutes  two  thirds  of 
the  solid  materials  of  the  gastric  juice,  does  its  office  by  es- 
tablishing the  lactic  fermentation,  such  as  is  seen  in  the 
changes  through  which  milk  passes  in  hot  weather.  The 
antiseptic  properties  are  important  in  order  to  prevent  putre- 
faction, which  would  be  so  liable  to  be  set  up  among  organic 
substances  in  such  a condition,  and  at  such  an  elevated  tem- 
perature as  the  stomach  usually  possesses. 

315.  Digestion  partly  depciidciit  on  Chemical  Action. — 
Thus  we  see  that  this  part  of  digestion  is  mainly  a chemical 
affair,  although  not  entirely  so : since  by  experiments  care- 
fully conducted  in  a vial  outside  of  the  body,  maintaining  the 
same  temperature  and  all  the  essential  conditions  of  digestion, 
the  process  goes  on  very  slowly  and  quite  imperfectly.  It 
was  found,  however,  that  a piece  of  meat  did  digest  in  a vial 
in  nine  hours  and  a half,  while  that  in  the  stomach  under 
precisely  similar  circumstances,  was  digested  in  one  hour  and 
a half. 

816.  Digestion  partly  a vital  Process. — Consequently  to 
say  exactly  what  stomach  digestion  is,  must  at  present  be  im- 
possible. We  can  only  say  that  it  is  a chemico- vital  process, 
essentially  a chemical  action  depending  upon  vital  power. 

317.  Movements  of  the  Stomach  in  Digestion.— In  order 
to  bring  the  food  in  contact  with  the  largest  amount  of  Gastric 
Fluid,  the  stomach,  by  an  instinctive  movement,  carries  its 
contents  over  the  greater  curve  in  it,  from  the  right  to  the 
left,  and  returns  it  in  a reverse  direction,  occupying  about 

What  constituent  is  it  that  is  primarily  essential  in  this  process?  315.  IIow  much  of 
the  process  thus  far  described  is  mainly  a chemical  one?  What  experiment  proves  it? 
.SIG.  What  definition  can  bo  given  of  Digestion  ? 317.  What  instinctive  movements  does 
the  stomach  seem  to  possess? 


AND  PHYSIOLOGY. 


175 


three  minutes  for  each  revolution.  And  in  order  that  all  of 
it  may  be  permeated  by  this  fluid,  contractions  frequently 
take  place  in  the  muscular  coat  of  the  stomach,  resembling  a 
churning  process. 

318.  Intestinal  Digestion,  Chyme. — The  process  thus 
far  is  Gastric  Digestion,  or  that  which  takes  place  in  the 
stomach,  and  the  object  accomplished  seems  to  be  the  con- 
version of  the  nitrogenous  constituents  of  the  food  into  albu- 
minose  called  histogenetic  digestion,  or  the  preparation  of  the 
food  to  be  made  into  the  tissues  of  the  body.  But  when  all 
the  food  is  thoroughly  dissolved,  or  made  into  a liquid  condi- 
tion called  Chyme,  the  Pyloric  orifice  is  opened,  and  the  food 
passes  into  the  Duodenum.  .When  it  arrives  here — and  never 
sooner,  in  a healthy  state — the  secretions  of  the  Liver,  Pan- 
creas, and  mucus  of  the  Intestine  mix  with  it,  performing  the 
second  or  Intestinal  digestion,  which  is  called  calorifacient  or 
heat  making,  since  it  prepares  the  food  which  supports  the  heat 
of  the  body.  The  process,  however,  is  somewhat  obscure,  aD 
though  it  is  certain  that  food  is  not  perfectly  fitted  for  absorp- 
tion until  it  has  well  completed  this  process. 

319.  Use  of  the  Pancreatic  Fluid. — The  Pancreatic  Fluid 
secreted  at  the  rate  of  from  five  to  seven  ounces  per  day,  re- 
sembles quite  closely  the  Saliva,  converting  starch  into  sugar, 
and  aiding  in  the  absorption  of  fatty  matters,  by  forming  an 
emulsion,  which,  however,  is  much  more  readily  formed  by 
the  presence  of  bile. 

320.  Action  of  the  Bile,  an  Antacid  and  Excre- 
tory Agent. — The  Bile,  thrown  out  at  the  rate  of  fifty-four 
ounces  a day,  seems  from  its  large  quantity  to  be  of  no 
little  importance.  And  since  the  juices  of  the  stomach  are 
mostly  acid  in  their  character,  it  seems  desirable  that  there 
should  be  some  counteracting  agent,  which  is  furnished  in  the 

SIS.  What  is  the  principal  thing  accomplished  hy  stomach  digestion  ? What  is  food 
called  after  it  has  passed  through  this  process  ? Describe  Intestinal  digestion  and  its 
use.  319.  What  amount  of  Pancreatic  fluid  is  secreted  daily  ? What  is  its  principal  use  ? 
320.  How  much  Bile  is  secreted  daily  ? 


8* 


170  II  l T C II  (;  O C K ’ S A N A T O M Y 

highly  alkaline  character  of  the  biliary  secretion.  Another 
use  of  the  bile  is  to  remove  certain  materials  from  the  blood 
(the  carbonaceous),  by  allowing  them  to  pass  off  with  the 
waste  portions  of  the  food,  the  liver  thus  performing  the  office 
of  an  excretory  organ.  The  liver  also  seems  to  possess  the 
power  of  forming  sugar  and  even  fat,  when  it  is  not  contained 
in  the  food,  thus  seeming  to  act  the  part  of  an  cquilibrator  in 
the  process  of  blood  making.  And  since  all  the  blood  re- 
turning from  the  small  intestines  passes  through  the  liver 
before  going  to  the  heart,  without  doubt  an  important  change 
is  accomplished  in  it  by  the  liver,  although  the  change  is  as 
yet  by  no  means  fully  understood. 

321.  Purposes  for  which  Food  is  required.  Two  kinds 
of  Materials  in  the  Food,  azotised  and  non-azotised. 
Azotised  Constituents.  Albamcn,  Fibrine,  Casein,  Gela- 
tin.— In  the  animal  body  we  find  that  food  is  required  for  at 
least  three  purposes  : First,  to  build  up  the  organism  at  the 
outset,  or,  in  other  words,  to  secure  its  first  growth.  Second, 
to  maintain  the  organism  at  its  normal  standard  after  its 
growth  is  complete,  or  to  furnish  material  to  supply  the  waste 
which  is  perpetually  going  on  while  life  lasts.  Third,  to 
maintain  the  proper  temperature  of  the  system.  Hence  there 
must  be  at  least  two  kinds  of  material  contained  in  the  food: 
one  that  will  sustain  and  promote  the  growth  of  the  tissues 
called  histogenetic,  and  another  that  will  keep  up  the  heat  of 
the  body  to  a proper  standard,  called  calorifacient.  The  first 
of  these  requisites  is  found  in  food  containing  Nitrogen,  called 
azotised,  and  the  other  in  that  with  no  Nitrogen,  called  non- 
azotised.  Of  the  azotised  food  the  most  important  constituents 
are  Albumen,  Fibrine,  Casein,  and  Gelatin.  Albumen  is  fami- 
liarly known  as  the  transparent  portion  of  an  egg  before  it  is 
cooked,  or  the  white  of  the  egg  after  a cooking  process.  It  ex- 
ists also  in  the  blood,  muscles,  and  bones  of  all  animals,  and  is 


How  is  its  alkaline  character  serviceable  ? What  other  processes  does  it  accoinplish  ? 
821.  What  three  purposes  is  food  required  for  ? Hence  what  two  kinds  of  food  must  be 
brought  into  the  system  ? Give  examples  of  azotised  food. 


AND  PHYSIOLOGY. 


177 


coagulated  or  made  hard  and  white  by  heat  or  mixture  with 
Nitric  Acid.  In  some  parts  of  vegetables  also,  especially  in 
the  seeds  and  fruit,  is  found  a substance  which,  from  its  re- 
semblance to  animal  albumen,  is  called  vegetable  albumen. 
Fibrine  exists  in  the  blood  and  muscles  of  animals,  forming 
the  coagulum  or  clot  of  blood,  and  the  proper  muscular  sub- 
stance. There  is  also  a corresponding  substance  in  plants 
known  as  vegetable  Fibrine.  Casein  closely  resembles  Albu- 
men in  its  constitution,  but  differs  in  many  of  its  physical 
properties.  For  while  Albumen  is  coagulated  by  heat.  Casein 
is  only  coagulated  by  lactic  and  acetic  acids.  Casein  is  best 
seen  in  cheese.  These  three  substances  are  the  essential  ele- 
ments of  nutrition  in  mammals,  and  though  every  other  prin- 
ciple may  be  supplied  in  the  food,  yet  the  body  is  insuflBciently 
nourished  without  Albumen  and  Fibrine.  Gelatin,  which 
exists  abundantly  in  the  cartilage  of  animals,  is  another 
azotised  principle  of  food.  This,  however,  of  itself  can  not 
support  life,  although  it  can  be  changed  into  albumen,  or 
some  of  its  compounds  by  the  action  of  the  fluids  of  the. 
stomach. 

322.  Non-azolised  Constituents. — Of  the  non-azotised 
constituents  of  food,  the  Saccharine  and  Farinaceous  and 
Oily,  are  the  principal  ones,  although  there  are  many  others 
of  less  importance.  Of  the  former,  the  principal  element  is 
starch,  while  the  sugar  is  secondary  or  subsidiary  to  it,  and 
in  the  latter  we  find  an  abundance  of  a Hydro-Carbon,  or  a 
compound  of  Hydrogen,  Carbon,  and  Oxygen,  and  all  are 
essential  elements  in  combustion. 

323.  Is  an  exclusively  Animal  or  Vegetable  Diet  the 
best  adapted  to  Man?  Testimony  of  Experience.  Ex- 
perience of  Dr.  Kane. — The  question  then  which  naturally 
suggests  itself  here  is,  whether  man  is  adapted  to  live  ex- 

Wbat  effect  has  heat  and  Nitric  Acid  upon  Albumen  ? Where  is  Fibrine  found  ? How 
does  Casein  differ  from  Albumen?  Will  Gelatin  (or  Jelly)  of  itself  support  life  ? 822. 
What  are  examples  of  non-azotised  kinds  of  food?  323.  Is  man  made  to  live  on  an  ex- 
clusively vegetable  or  animal  diet  ? 


178 


HITCHCOCK’S  ANATOMY 


clusively  upon  vegetable  or  animal  diet.  An  answer  comes 
to  us  from  both  experience  and  chemistry.  For  while  on  the 
one  hand  hundreds  of  examples  are  adduced,  as  showing  that 
some  men  have  lived  to  a green  old  age  in  solid  health,  who 
liavo  entirely  refrained  from  animal  diet,  and  many  others 
who  probably  Avould  have  shortened  their  lives  a score  of 
years  by  the  use  of  animal  food,  have  prolonged  it  by  adopt- 
ing a vegetable  regimen,  an  equal  number  of  cases  can  be 
mentioned  to  show  that  a mixed  diet  has  promoted  equally 
long  and  healthy  lives.  The  geographical  distribution  of  man, 
as  well  as  the  manner  of  life,  also  furnishes  valuable  evidence 
in  this  case.  Travelers  who  have  visited  the  polar  regions,  and 
pre-eminently  Dr.  Kane,  give  us  undoubted  testimony  of  the 
necessity  of  eating  meat  and  animal  fat  to  keep  the  body  in 
health:  since  the  low  temperature  not  only  requires  a greater 
amount  of  combustive  material,  but  this  greater  energy  of 
respiration  produces  a more  rapid  w'aste  of  all  the  tissues  of 
the  body^  requiring  a more  abundant  supply  of  azotised  and 
non-azotised  material  to  supply  the  deficiency.  And  on  the 
other  hand  experience  shows  that  in  tropical  climates  stimu- 
lating food  and  drink  should  be  avoided,  because  the  high 
temperature  of  the  atmosphere  depresses  vital  energy,  and 
consequently  less  material  for  supporting  animal  heat  is  re- 
quired with  a corresponding  decrease  in  the  waste  of  the 
body. 

324.  Example  of  tlie  Esquimaux. — As  examples  of  these 
principles  one  traveler  among  the  Esquimaux  relates  that  these 
people  relish  very  heartily  tallow  candles  as  a dessert  for  din- 
ner. Another  states  that  he  has  seen  the  Greenlanders  eat 
from  twenty  to  thirty  pounds  of  blubber,  or  whale-fat,  at  one 
meal.  This,  however,  was  a sufficiency  of  food  to  them  for 
two  or  tliree  days. 

Give  the  testimony  of  experience.  Give  the  arj^nment  derived  from  difference  in 
climate.  What  kind  of  food  is  necessary  to  support  life  in  polar,  and  what  in  tropical 
countries  ? 324.  State  luxurious  articles  of  diet  among  Esquimaux  and  Greenlanders. 
How  much  will  a Greenlander  sometimes  cat? 


AND  PHYSIOLOGY. 


179 


825.  Voice  of  Chemistry —Chemistry,  however,  teaches 
us  that  we  can  find  in  the  vegetable  world  all  the  principles 
necessary  to  support  the  body  without  using  animal  food. 
And  although  the  vegetable  kingdom  contains  those  elements 
which  will  support  life  in  many  instances,  yet  we  know, 
as  a general  riile^  that  we  find  man  in  the  highest  degree 
of  bodily  and  mental  vigor,  only  when  he  makes  use  of 
a mixed  diet.  And  we  also  find  that  all  animals  which  are 
the  most  active  in  their  habits,  and  rapid  in  their  motions,  are 
feeders  upon  animal  flesh.  There  is  also  a race  of  half  civil- 
ized savages,  the  Guanchos,  who  spend  the  greater  part  of 
their  lives  in  the  saddle  and  constantly  in  a state  of  great 
activity,  who  live  almost  exclusively  upon  animal  diet,  and 
yet  are  unequaled  in  their  powers  of  physical  endurance,  and 
live  lives  fully  equal  to  the  average  in  duration. 

326.  Argument  from  the  Teeth. — The  strongest  physio- 
logical argument  in  favor  of  a mixed  diet,  is  found  in  the 
conformation  of  the  teeth  and  alimejito^  canal  of  man.  In 
those  animals  which  live  exclu^f^el^lipon  animal,  diet,  the 
teeth  are  sharp  and  pointed,  with  a very  short  alimentary 
tube,  since  the  nutrient  portion  of  the  food  is  readily  absorbed 
by  the  lacteals.  On  the  other  hand,  the  teeth  of  vegetable 
feeding  animals  are  smoothed  upon  their  upper  surfaces,  being 
adapted  to  crush  vegetable  substances,  and  the  alimentary 
tube  very  long,  since  the  nutrient  portion  of  vegetable,  food  is 
not  so  readily  parted  with.  Now  in  man  we  ftid  neither  of 
these  apparatuses  perfectly  complete,  but  an  admixture  of 
both.  Part  of  the  human  teeth  are  of  the  carnivorous  or 
flesh  eating  kind,  and  another  part  of  the  herbivorous  or 
vegetable  eating  kind  : but  each  of  them  so  modified,  that 
either  kind  of  food  can  be  readily  prepared  for  digestion. 
The  alimentary  canal  too  is  intermediate  between  that  of  the 
carnivorous  and  herbivorous  type,  being  equally  well  adapted 

325.  What  does  chemistry  teach  on  this  subject?  How  does  great  bodily  activity 
affect  the  diet  as  illustrated  by  the  Guanchos  ? 326.  State  the  argument  derived  from 

the  teeth,  What  two  kinds  of  teeth  are  found  in  man  ? 


180 


HITCHCOCK’S  ANATOMY 


to  the  digestion  of  animal  or  vegetable  food,  or  an  admixture 
of  both. 

327.  Conclusions. — The  kind  of  food  which  is  the  most 
perfectly  adapted  to  the  constitution  of  man,  seems  to  be  de- 
termined by  the  following  rules,  based  upon  the  temperature 
of  the  climate,  the  habits  or  employments  of  life,  and  the 
health  of  the  individual. 

First.  The  lower  the  temperature  the  greater  the  amount 
of  animal  heat  necessary  for  the  support  of  life,  which  re- 
quires the  fattest  portions  of  the  meat. 

Second.  The  more  active  the  habits  of  the  individual,  and 
the  greater  the  amount  of  exposure  in  the  open  air,  the  greater 
the  demand  for  animal  food. 

Third.  If  the  system  be  suffering  under  inflammation  of 
any  sort,  or  if  there  be  any  tendency  to  inflammation,  animal 
food  should  be  used  very  sparingly,  or  entirely  dispensed 
with. 

Fourth.  That  diet  seems  to  be  the  most  perfectly  adapted 
to  the  human  constitution  in  all  climates  and  seasons,  which 
is  composed  of  animal  and  vegetable  food  in  the  proportion  of 
one  to  two,  or  one  third  by  weight  of  animal  food  to  two 
thirds  of  vegetable  food.  This  proportion  is  the  basis  of  the 
diet  scales  of  the  United  States  and  British  Navies. 

828.  Use  of  the  Lacteals. — The  use  of  the  Lacteals  is  to 
absorb  the  Chyle  or  nutrient  material  from  the  contents  of  the 
intestines,  and  .carry  it  into  the  general  circulation.  The 
force  by  which  this  fluid  is  taken  from  the  alimentary  canal, 
is  by  no  means  understood  at  present,  unless  it  be  capillary 
attraction. 

329.  The  Chyle. — The  Chyle  is  a white  liquid  somewhat 
thicker  than  milk,  and  is  made  up  of  a solution  of  albumen 
containing  minute  globules,  or  cells,  which  are  mostly  spher- 

827.  What  four  conclusions  arc  drawn  from  this  whole  subject  of  diet?  328.  What  is 
the  function  of  the  Lacteals?  What  is  the  force  that  circulates  the  Chyle?  829.  De< 
scribe  the  Chyle. 


AND  PHYSIOLOGY. 


181 


ical  and  about  3 o¥o ©th  of  an  inch  thick,  and  Chyle  Cor- 
puscles, which  are  simple  cells  about  e ©Voth  of  an  inch  in 
diameter. 

330.  The  Place  where  the  Chyle  enters  the  Blood. — 
Principle  of  Venturi. — As  already  mentioned  the  Chyle  en- 
ters the  blood  through  the  left  Subclavian  vein  of  the  neck. 
It  is  not,  however,  simply  by  the  opening  of  one  vessel  into 
another  that  this  is  accomplished,  but  advantage  is  taken  of 
the  union  of  two  currents,  so  that  by  their  combined  force 
the  chyle  is  drawn  in  towards  the  heart.  The  mouth  of  the 

Pig.  18t. 


Position  of  the  Thoracic  Duct  and  the  Veins  of  the  Neck  where  it  emx>ties. 

S.  V.  Subclavian  Vein.  J.  Jugular  Vein.  D.  Thoracic  Duct. 

Thoracic  Duct,  however,  is  provided  with  valves  to  prevent 
the  blood  from  entering  it,  in  case  obstruction  in  the  veins 
should  occur.  And  it  is  a physical  fact  that,  when  a small 
tube  is  inserted  perpendicularly  into  the  lower  side  of  a hori- 
zontal conical  pipe,  in  which  water  is  flowing  from  the  nar- 

Give  the  size  of  the  Chyle  Corpuscles.  880.  Give  the  description  of  the  hydraulic 
principle  by  which  the  chyle  is  drawn  towards  the  heart. 


182 


II  ITCH  cock’s  anatomy 


Fig.  188. 


Illustration  of  the  Principle  of  Ven- 
turi. When  a current  passes  through  a 
large  tube,  if  another  smaller  tube  open 
into  its  side,  the  current  in  this  tube 
will  be  drawn  into  the  large  tube,  even 
against  the  force  of  gravity. 


rower  to  the  wider  portion, 
if  the  vertical  tube  be  made 
to  dip  into  a vessel  of  water, 
not  only  will  the  water  of  the 
larger  pipe  not  descend  into 
the  vessel,  but  it  will  draw 
up  the  water  through  the 
small  tube  so  as  to  empty 
the  vessel.’’  This  is  called 
“the  principle  of  Venturi,” 
and  is  well  illustrated  by  the 
entrance  of  the  Thoracic  Duct 
into  the  Subclavian  vein,  as 
seen  in  the  cut  No.  187.  A 
diagram  illustrating  the  same 
principle  is  seen  in  Fig.  188, 
the  arrows  representing  the 
direction  of  the  currents,  and 
the  smaller,  perpendicular 
tube  illustrating  the  Thoracic 
duct  at  its  entrance  between 
the  veins  of  the  neck. 


331.  The  lymphatics. — The  Lymphatics  in  general 
structure  and  function  resemble  the  lacteals.  The  lacteals, 
however,  are  designed  exclusively  for  promoting  the  growth 
of  the  body  by  adding  nutrient  materials,  while  the  lympha- 
tics give  up  to  the  general  circulation  not  only  useful  pro- 
ducts, but  all  those  which  are  absorbed.  Hence  whatever  is 
presented  to  the  mouths  of  the  lymphatics,  is  carried  into  the 
general  system,  while  injurious  products  are  not  usually  taken 
up  by  the  lacteals.  (See  also  page  284.) 

332.  The  Action  effected  by  the  lymphatics. — Since 
the  Lymphatics,  as  already  described,  are  found  in  every 


Illustrate  the  principle  of  Venturi.  831.  Give  the  general  structure  of  the  Lympha- 
tics. state  the  probable  differences  in  function  between  these  and  the  Lacteals. 


AND  PHYSIOLOGY. 


183 


part  of  the  body  in  great  numbers,  and  are  almost  constantly 
at  work  in  removing  the  waste  particles,  it  follows  that  in 
process  of  time  a large  part,  or  even  the  whole  of  the  body, 
will  be  removed.  And  it  is  generally  admitted  that  the 
whole  body  is  actually  renewed  every  few  years,  although 
the  precise  number  can  not  be  stated,  since  so  many  circum- 
stances modify  the  change,  such  as  exercise,  the  amount  of 
food  taken,  and  climate,  as  well  as  other  causes  not  so  easily 
understood.  It  is,  however,  quite  probable  that  the  period 
of  ten  years  is  sufficient  to  complete  the  change  in  most  in- 
dividuals, and  the  number  is  stated  by  some  as  low  as  seven. 


HYGIENIC  INFERENCES. 

333.  1.  From  the  structure  and  functions  of  the  Digestive 
Organs  we  can  derive  some  hints  as  to  the  manner  of  pre- 
venting acute  and  chronic  diseases  in  them. 

334.  Danger  of  Eating  too  much— 2.  We  see  that  there 
is  a great  danger  of  eating  too  much.  Large  quantities  of 
food  distend  the  coats  of  the  stomach,  and  give  too  much  labor 
for  them  to  perform.  As  a natural  consequence  the  gastric 
glands  are  weakened  from  excessive  action,  and  then  indiges- 
tion or  some  other  diseased  action  is  sure  to  follow.  And  in 
how  much  better  health  wmld  multitudes  in  the  higher  classes 
of  society  be  kept,  if  some  of  the  numerous  dishes  they  use 
were  omitted!  And  in  this  country  the  remark  applies  to 
nearly  all  classes. 

335.  We  are  apt  to  eat  too  many  Kinds  of  Food. — 3.  We 
also  see  that  our  meals  are  generally  made  up  of  too  7nany 
kinds  of  food.  In  the  habits  of  the  lower  animals  we  dis- 
cover a great  simplicity  of  diet.  Even  in  those  whose  ana- 
tomical structure  closely  resembles  that  of  man,  the  appetites 

832.  ITow  jrreat  changes  are  effected  in  the  body  by  the  Lymphatics?  In  what  length 
of  time  is  the  body  probably  entirely  renewed?  334.  What  is  the  injury  from  eating 
too  much  ? 335.  What  is  said  about  eating  too  many  kinds  of  food  ? 


184 


HITCHCOCK’S  ANATOMY 


are  easily  satisfied  by  the  simplest  food.  Nor  does  man’s 
intellectual  superiority  demand  a greater  variety  in  diet,  all 
that  is  requisite  being  the  materials  necessary  to  support  the 
growth  of  the  different  tissues. 

335a.  4.  It  is  evident  that  condiments  and  spices  shoidd 
he  always  used  very  sparinyhj^  and  generally  s])ices  not  at 
all.  To  be  sure  nature  seems  to  indicate  the  want  of  a mode- 
rate supply  of  salt  (perhaps  for  the  juices  of  the  stomach), 
but  pepper,  mustard,  and  ketchup  excite  the  coats  of  the 
stomach  to  an  action  that  is  unnatural.  And  it  seems  to  bo 
a law  of  the  system  that  stimulants  and  opiates,  if  used 
regularly,  must  be  constantly  increased  in  quantity,  other- 
wise they  will  lose  their  effect,  and  disorder  will  follow.  In 
fine,  all  experience  seems  to  prove  that  the  demands  of  nature 
for  food  are  very  simple  and  easily  gratified ; but  the  appetite 
may  bo  so  trained  as  to  loathe  every  thing  of  a simple  and 
natural  kind,  and  be  satisfied  only  with  the  stimulating  com- 
pounds of  modern  cookery.  The  law  of  nature,  however, 
cannot  be  reversed,  that  he  who  lives  in  the  simplest  manner 
lives  the  longest,  and  suffers  the  least  from  pain  or  disease. 

336.  Wc  must  not  eat  too  fast. — 5.  Most  persons  eat  too 
fast.  No  time  is  gained  on  the  sum  total  of  life,  by  taking 
any  from  that  demanded  by  nature  for  eating  and  digesting 
food.  A fortune  or  great  reputation,  it  is  true,  may  some- 
times be  gained  a little  quicker  by  using  the  time  which  the 
stomach  rightfully  claims,  yet  the  penalty  for  such  robbery  is 
a shorter  life,  or  a disease  which  makes  life  miserable. 

337.  Tlie  Time  of  Eating, — 6.  We  see  that  the  time  of 
eating  should  not  encroach  tipon  the  hours  devoted  to  sleep ^ 
or  those  of  hard  labor.  During  sleep  the  brain  needs  quiet; 
but  if  there  be  any  function  going  on  such  as  that  in  the 
earlier  stages  of  digestion,  the  brain,  as  a matter  of  necessity, 

Does  intellectual  superiority  require  so  great  a variety  as  is  often  introduced  ? 335. 
Why  are  condiments  ai»d  spices  to  bo  used  very  sparingly  ? What  are  the  demands  of 
nature  upon  the  appetite?  IIow  much  may  the  appetite  be  perverted?  336.  What 
danger  in  eating  too  fust?  337.  What  time  during  the  day  should  wc  eat? 


AND  PHYSIOLOGY. 


185 


must  labor  till  the  process  is  accomplished,  and  as  a result, 
dreams  or  imperfect  trains  of  thought  will  produce  that  kind 
of  sleep  which  cannot  refresh  the  body.  If  again  the  time 
for  meals  precede  or  follow  very  closely  upon  hard  labor,  a 
law  of  nature  is  broken,  and  the  penalty  is  sure  to  follow. 
The  nervous  energy  cannot  be  immediately  called  off  from 
the  part  to  which  it  has  for  some  time  been  directed  (whether 
to  the  brain  or  the  muscles),  and  consequently  the  stomach 
for  a while  must  lie  nearly  inactive.  Hence  a short  season 
of  relaxation  from  all  active  exercise,  whether  mental  or 
physical,  just  before  and  after  meals,  is  very  conducive  to 
health,  since  in  the  former  case  the  circulation  is  equalized, 
and  the  brain  can  prepare  its  energies  to  expend  them  on  the 
stomach,  while  after  meals  the  whole  force  of  the  nervous  in- 
fluence is  needed  for  a time  by  the  digestive  function  before  it 
can  be  directed  to  the  muscles  for  exercise.  Even  a short 
time  after  dinner  devoted  to  a nap  promotes  digestion  quite 
rapidly,  although  the  habit  often  is  an  inconvenient  one,  to 
say  the  least,  since  if  by  unavoidable  circumstances  it  is  omit- 
ted for  once,  the  person  feels  uncomfortable  the  rest  of  the 
day. 

838.  Danger  of  employing  Stimulants  for  weak  Stom- 
achs.— 7.  We  see  the  error  and  danger  of  a very  common 
practice : that  whm  the  digestive  organs  become  weak^  and 
the  appetite  is  poor ^ stimulants  are  employed  to  waken  the 
stomach  to  crave  more  food  than  it  can  digest.  This  only 
aggravates  the  difiiculty  and  makes  a demand  for  stronger 
stimulants,  and  thus  often  is  the  system  prematurely  worn 
out.  Whereas,  would  men  follow  nature  and  when  a dimin- 
ished appetite  teaches  them  to  eat  less  and  give  the  organs  an 
opportunity  to  rest,  they  would  ere  long  rally  and  digest  all 
that  is  necessary  to  give  tone  and  energy  to  the  system.  To 

Why  should  not  hard  labor  and  a full  meal  come  closely  together?  How  does  a short 
nap  after  dinner  affect  digestion  ? What  is  a serious  objection  to  the  habit?  338.  What 
danger  results  from  using  stimulants  to  help  weak  stomachs  ? Should  we  eat  more  than 
the  natural  appetite  craves? 


186 


II  I T C 11  C O CMC  ’ S A X A T O M Y 


eat  more  than  the  stomach  craves,  is  not  the  way  to  gain 
strength,  but  to  increase  weakness  and  shorten  life. 


COMPARATIVE  SPLANCHNOLOGY. 


339.  Digestive  Organs  of  Mammals. — In  many  mam- 
mals the  digestive  organs  in  their  general  arrangement  and 
construction  resemble  those  of  man. 


Fig.  189. 


Maxillary  Gland. 
Trachea. 


Lungs. 

Heart. 


Liver. 
Gall  Bladder. 


Colon. 
Caecum. 
Small  Intestine. 


Parotid  Gland. 


Pharynx. 

Gullet. 


Thorax. 


Midriff. 

Stomach. 

Pancreas. 

Soleen. 

Kidneys. 

Colon. 

Abdomen. 

Eectum. 

Bladder. 


Digestive  Apparatus  of  an  Ape. 


340.  Esophagus  of  the  Horse, — In  the  Horse,  however, 
at  the  lower  end  of  the  Esophagus,  there  is  a sickle-shaped 


340.  How  does  tlio  Esophagus  of  tho  Horse  differ  from  that  of  a man? 


AND  PHYSIOLOGY. 


187 


fold  of  lining  membrane,  which  makes  it  impossible  for  this 
animal  to  vomit. 

341.  Stomach  of  Ruminants. — Mammals,  as  a general 
rule,  have  very  simple  stomachs,  and  particularly  those 
which  live  upon  animal  food.  But  in  those  herbivorous 
ones  which  chew  the  cud,  this  organ  consists  of  four  cavities, 

Fig.  190. 


Gullet. 

Esophiigean  Groove. 

Mauiplies. 


Duodenum. 

Pylorus.  The  Eennet.  2d  Stomach.  Paunch. 

Stomach  of  the  Sheep. 

the  Ingluvies  or  ‘^Paunch,’’  the  Reticulum  or  Honey 
Comb,’’  the  Omasum  or  ‘^Many  Plies,”  and  the  Abomasum 

Fig.  191. 

Gullet. 

Esophageal  Groove. 

Mauiplies,  or  Third 
Stomach. 

Eennet,  or  Fourth 
Stomach. 

Duodenum. 

Pylorus.  Second  Stomach.  Paunch. 

Interior  of  Stomach  of  the  Sheep. 

341.  What  is  the  number  of  stomachs  in  herbivorous  animals  ? Give  the  names  cf 
each. 


188 


HITCHCOCK’S  ANATOMY 


or  ^ Red/’  As  tlio 
food  enters  tlio  Inglu- 
vies,  it  is  simply  mixed 
with  the  fluid  secreted 
by  its  coats,  when  it 
passes  into  the  Reticu- 
lum, where  it  not  only 
receives  additional  se- 
cretions, but  is  made 
into  little  ‘‘cuds”  or 
“pellets,”  which,  when 
the  animal  is  at  rest, 
are  returned  to  the 
mouth  for  the  purpose 
of  re-chewing  and  mix- 
ing with  the  saliva. 
After  this  process  is 
completed,  they  are  sent  into  the  Omasum,  which  cavity 
seems  designed  to  prepare  the  food  to  enter  the  fourth  stom- 
ach where  the  true  process  of  digestion  takes  place.  And 
it  is  from  this  fourth  stomach  or  Abomasum,  that  the  Rennet 
is  taken  from  young  calves,  and  used  by  cheesemakers  for  the 
purpose  of  coagulating  the  milk. 

342.  Reason  of  this  Complex  Stomach. — The  probable 
reason  of  such  a complicated  stomach  in  these  animals  is  that 
since  they  have  such  poor  means  of  self-defense,  they  need  to 
crop  their  food  as  quickly  as  possible,  and  then  retire  to  a 
safe  place  to  masticate  it.  And  it  is  also  partly  owing  to  the 
fact  that  vegetable  substances  require  a longer  process  for  di- 
gestion than  does  animal  food. 

343.  Icnj^th  of  Intestine. — The  length  of  the  Intestine 
depends  as  a general  rule  upon  the  food  used  by  the  animal. 


Pig.  192. 


stomach  of  the  Ox.  A.  Paunch.  7?.  Re- 
ticulum. C.  Omasum.  D.  Abomasum. 
E.  Pylorus.  F.  Duodenum.  G.  Esopha- 
gus. 


Give  tlie  process  of  die  wing  the  cud  in  these  animals.  842.  What  is  one  important 
reason  for  this  eoinplicated  arrangement?  843.  Upon  what  does  the  length  of  Intestine 
ilepeml  ? 


AND  PHTSIOLOGY. 


i89 


the  vegetable  feeders  having  a long  tube,  and  the  flesh  feeders 
a short  one,  since  animal  food  is  so  easy  of  stomach  digestion, 
and  the  nutrient  portion  of  it  so  readily  taken  up  by  the 
lacteals.  Thus  the  ox  has  an  alimentary  tube  fifteen  or 
twenty  times  the  length  of  the  body,  amounting  in  a full 
grown  animal  to  150  feet,  the  sheep  one  twenty-eight  times  its 
length,  while  many  of  the  carnivora  exhibit  one  only  about 
three  times  the  length  of  the  body.  The  true  Cetacea  or  Whale 
tribe  are  the  only  ones  which  do  not  have  a marked  distinc- 
tion between  the  large  and  small  intestine. 

344.  The  liver, — The  Liver  as  in  man  is  one  of  the 
largest  organs  in  the  body,  and  is  much  more  divided  into 
lobes  in  carnivorous  than  herbivorous  animals.  It  is  smallest 
and  least  divided  in  those  animals  with  compound  or  rumi- 
nating stomachs. 

845.  Bill  of  Birds. — Birds  are  destitute  of  teeth,  since 
the  process  of  mastication  is  carried  on  in  a certain  portion 
of  the  alimentary  canal.  But  the  horny  investment  of  the 
jaws  known  as  the  bill,  is  harder  in  birds  of  prey,  and  those 


Fiq,  193, 


Os  Ilyoidcs. 


Head  of  the  Woodpecker. 


that  feed  on  fruit  and  nuts,  as  Parrots,  and  in  Woodpeckers. 
The  bill,  or  rather  mouth,  of  Ducks  and  Geese  is  lined  by 
a tender  membrane,  in  order  that  they  may  be  partially 

What  is  the  length  of  the  Intestine  of  the  Ox?  Of  the  Sheep?  Give  the  propor- 
tional length  of  Intestine  in  Carnivorous  Animals.  344.  What  difference  in  the  Liver 
between  flesh  and  herbivorous  animals  ? 345.  Why  are  Birds  destitute  of  teeth  ? 

What  Birds  have  the  hardest  bills?  What  peculiarity  in  the  lining  membrane  of  the 
mouth  of  Ducks,  etc.  ? 


190 


HITCHCOCK’S  ANATOMY 


FiO.  194. 


Digestive  Apparatus  of  Fowl.  a.  Esophagus,  h.  Crop  or  Ingluvies.  c.  Pro- 
ventriculus.  d.  Gizzard,  e.  Liver.  /.  Gall-Bladder,  g.  Pancreas,  h.  Duodenum. 
i.  Small  Intestine.  k.  Cteca.  1.  Large  Intestine,  m.  Ureter,  n.  Oviduct. 
o.  Cloaca. 

guided  in  the  selection  of  their  food  from  the  soft  mud  by  the 
sense  of  touch. 

34G.  Stomach  of  Birds.  — The  Gizzard.  — The  true 
stomach  of  birds  consists  of  two  divisions.  There  are,  how- 


84G.  State  the  usual  number  of  stomachs  in  Birds. 


AND  PHYSIOLOGY, 


191 


ever,  three  enlargements  of  the  alimentary  canal,  all  of  which 
prepare  the  food  for  assimilation.  The  first  of  these  is  the 
‘‘ Ingluvies’^  or  ‘‘Crop,’’  where  the  food  is  softened  by  the 
mucous  secretion  of  the  lining  membrane.  Then  as  it  passes 
along  into  the  “ Proventriculus,”  it  receives  the  gastric  juice 
from  the  gastric  glands  which  line  it.  The  second  stomach, 
the  “Gizzard,’"  is  round  and  flat  and  made  up  of  powerful 
muscular  fibres,  except  in  birds  of  prey,  where  it  is  thinner 
in  texture.  In  gallinaceous  birds  its  lining  membrane  is  of 
a horny  consistency,  which,  with  the  powerful  muscular  fibres, 
render  it  an  organ  of  mastication  to  granivorous  birds.  Gravel 
and  angular  stones  are  purposely  swallowed  by  these  birds 
to  aid  in  the  digestive  or  grinding  process. 

847.  Teeth  and  Jaws  of  Reptiles —Eeptiles  need  teeth 
only  to  seize  and  retain  their  prey,  since  whatever  food  is 
taken  by  them,  is  swallowed  without  mastication,  which  is 
one  reason  why  the  jaws  and 
throats  of  serpents  are  so 
very  capacious.  A peculi- 
arity in  their  bony  construc- 
tion renders  this  possible, 
for  the  jaw  is  not  made 
up  of  one  or  at  most  two 
pieces  as  in  mammals,  but  of 
several  segments,  which  rea- 
dily move  one  upon  another, 
as  if  with  different  articula- 
tions. 

348.  The  Tongue. — The  Tongue  is  used  as  an  instrument 
for  the  capture  of  prey  by  many  reptiles.  Frogs  and  Sala- 
manders are  able  to  thrust  it  out  with  great  rapidity  and 

Give  the  names  of  each.  Describe  the  Gizzard.  Why  are  caravel  and  stones  swallowed 
by  granivorous  birds?  Which  is  the  true  stomach ? 847.  What  is  the  only  use  of  teeth 
in  reptiles?  State  the  reason  why  the  jaws  are  so  capacious.  Of  how  many  bones  are 
they  frequently  made  up  ? 348.  Of  what  use  is  the  tongue  to  some  reptiles? 

9 


FiG.  195. 


It  ma 


mi 


Head  of  the  Kattlesnake.  mi.  Lower 
Jaw.  t.  Tympanic  Bone,  ma.  Mastoid 
Bone,  m.  Upper  Jaw, 


102 


HITCHCOCK’S  anatomy 


coil  it  upon  insects  or  any  other  object.  This  property,  to- 
gether with  the  adhesive  mucus  found  upon  it,  makes  it  for 
these  animals  a very  serviceable  apparatus  in  obtaining 
food. 

349.  Esophageal  Tcclli. — In  many  animals  of  this  de- 
scription the  Esophagus  is  lined  with  bony  processes  pointing 
downwards,  called  Esophageal  teeth,  which  greatly  aid  in 
swallowing  the  large  masses  which  they  are  accustomed  to 
force  into  their  stomachs. 

850.  Stomach.  — length  of  Intcsliiie. — The  Stomach 
seems  to  be  only  a dilatation  of  the  Intestine.  In  many 
species  it  is  divided  into  two  cavities  resembling  those  of  a 
bird,  (Fig.  196)  : the  first  a Gizzard,  or  an  organ  made  up 
of  stout  muscular  fibers,  and  the  second  a thin  walled  and 
secreting  cavity.  In  Crocodiles  it  is  round,  and  the  muscular 
coat  is  very  thick,  in  order  to  reduce  to  a digestible  size 
the  coarse  food  which  it  so  greedily  devours.  The  length 
of  the  intestine  in  most  reptiles  is  about  twice  the  length 
of  the  body  ; in  Lizards,  however,  it  is  only  about  the 
same  length  as  the  body.  A cloaca  or  additional  rectum 
is  sometimes  found  in  these  animals,  as  is  the  case  among 
birds. 

351.  Stomach  and  Intestine  of  Fishes — In  many  Fishes 
the  intestinal  tube  extends  from  the  mouth  directly  through 
the  animal  without  any  enlargement  for  the  stomach,  or  any 
convolutions,  as  is  the  case  with  all  the  animals  thus  far  con- 
sidered on  this  subject,  and  with  which  no  organ  of  secretion 
is  connected,  except  the  liver.  The  intestinal  canal,  however, 
is  generally  more  or  less  convoluted,  and  ordinarily  it  is  short. 
In  the  Shark  the  stomach  is  parceled  out  by  constrictions  and 


With  wliat  is  it  covt'red,  that  renders  it  more  serviceable  as  an  instrument  of  capture  ? 
849.  What  is  said  of  Esophageal  teetli?  850.  Is  the  stomach  a simple  or  complex  cav- 
ity ? What  is  the  uvuragi;  length  of  intestine  among  reptiles  ? What  is  said  of  a cloaca? 
851.  In  what  condition  is  tlio  stomach  found  in  mostlishos?  What  peculiarity  is  met 
■within  the  Shark  ? ' 

I 


AND  PHYSIOLOGY.  193 


Fig.  196. 


Intestine,  cl.  Cloaca.  /.  Liver,  o.  Ovary,  o'.  Eggs.  t.  Trachea,  p.  p'.  Lungs,  vt. 
Ventricle,  e.  e'.  Auricles,  a.  ad.  a'.  Aorta,  ac.  Carotid  Arteries.  ve.  Vena?  Cavje. 
vp.  Pulmonary  Vein. 

inversions  into  several  divisions  with  valve-like  appendages 
between  them. 

852.  liver. — Fishes  have  usually  a large  soft  Liver  com- 
pletely saturated  with  an  oil.  Its  form  is  various,  but  is 


C52.  Speak  of  the  Liver  of  fishes. 


194 


HITCHCOCK’S  ANATOI^rY 


often  imperfectly  divided  into  two  lobes.  The  oil  that  is  ex- 
pressed from  the  liver  of  the  Cod  Fish,  is  often  used  with 
great  efficacy  in  the  early  stages  or  symptoms  of  consumption. 

Fig.  197.  353.  Pyloric  Appendages. 

— In  many  fishes  with  bony 
skeletons  there  is  found  a cu- 
rious set  of  gland-like  organs 
called  Pyloric  appendages. 
They  vary  in  number  from 
two  in  the  Plaice,  to  two 
hundred  in  the  Mackerel,  and 
always  cither  encircle  the 
pylorus,  or  are  found  near 
the  upper  end  of  the  intestine. 
These  appendages  are  inva- 
riably absent  in  those  fishes 
which  have  an  imperfectly 
formed  stomach,  and  by  some 
are  considered  as  analogous 
to  a Pancreas  in  function. 

354.  Salivary  Glands. — 
Salivary  Glands  are  wanting 
in  fishes,  but  their  place  is 
supplied  by  an  increased  de- 
velopment of  the  mucous 
glands  of  the  mouth. 

855.  Digestive  Organs  in 
the  Invertebrates.— In  the 
Polyps  of  the  Radiate  ani- 
mals, we  have  the  simplest 
form  of  digestive  apparatus, 
viz.,  a simple  sack,  with  a 
mouth  to  receive  the  food 
and  to  disgorge  the  refuse,  as  is  seen  in  Fig.  198,  A.  Other 
Polyps,  however,  have  two  openings  in  their  stomach  or  sack, 
as  shown  in  Fig.  198,  B. 


Digestive  Appunitus  of  a Beetle,  a. 
Head.  h.  Crop  and  Gizzard,  c.  Biliary 
Vessels.  (J.  Intestine,  e.  Secreting  Or- 
gans. 


AND  PHYSIOLOGY, 


195 


Fig.  198. 


A 


Digestive  Apparatus  of  Unicellular  Animals. 


356.  The  Hydra. — Fig.  199,  an  unicellular  animal,  is  an 
example  where  the  simplest  sort  of  digestive  organs  is  ex- 
hibited. The  animal  is  little 
else  than  a gelatinous  sac, 
and  if  it  be  turned  inside  out 
digestion  will  still  go  on. 

Thus,  ‘’notwithstanding  the 
simplicity  of  its  structure, 
this  creature  feeds  not  merely 
upon  algae,  but  upon  young 
active  animalcules,  the  young  of 
crustaceans,  etc.  ; any  one  of 
these,  when  they  happen  to 
came  in  contact  with  one  of 
the  tentacular  filaments,  be- 
ing usually  retained  by 
adhesion  to  it.  As  this 
filament  shortens  itself,  all 

. . Hydra  or  Fresh  Water  Polyp,  a.  En- 

the  surviving  filaments  ap-  trance  and  Exit  to  stomach. 

ply  themselves  to  this  captive 

particle,  so  that  it  becomes  gradually  inclosed,  and  grad- 


356.  What  is  the  process  of  digestion  in  the  hydra  ? 


196 


HITCHCOCK’S  ANATOMY 


ually  shortening,  so  as  at  last  to  bring  the  prey  close  to  the 
surface  of  the  body.  The  spot  with  which  it  is  brought  in 
contact,  then  slowly  retracts,  and  forms  at  first  a shallow  de- 
pression, gradually  becoming  deeper  and  deeper,  into  which 
the  prey  sinks  little  by  little,  for  some  time,  however,  con- 
tinuing to  project  from  the  surface.  The  depression  at  last 
assumes  a flask-like  form,  by  the  drawing  in  of  its  margin, 
and  finally  its  edges  close  together,  and  its  prey  is  entirely 
shut  in.  This  gradually  passes  to  the  center  of  the  body, 
where  its  soluble  parts  are  dissolved,  whilst  in  the  mean  time 
its  external  portion  recovers  its  pristine  condition.” 

357.  Other  Radiates  have  an  alimentary  canal  more  com- 
plicated, having  a stomach  and  csecal  appendages  that  appear 
to  perform  the  oflSce  of  a liver.  Some  of  the  Echinoderms 
have  teeth;  in  the  Echinidm  is  a curious  apparatus  in  the 
mouth  called  Aristotle’s  lantern. 

358.  Another  form  of  the  digestive  apparatus  consists  of  a 
central  cavity,  wdth  branches  extending  through  every  part 
of  the  body. . Fig.  200  shows  this  in  one  of  the  Articulated 
animals,  an  Arachnoid  Crustacean,  the  Ammothea  pycnog- 
onoides.  This  arrangement  is  found  in  several  other  classes 
of  the  Invertebrates. 

359.  The  Crustaceans  are  generally  furnished  with  two 
upper  jaws,  called  Mandibles,  which  move  laterally ; and  be- 
hind these,  two  pairs  of  weaker  and  softer  lower  jaws,  which 
are  sometimes  changed  into  suckers  and  legs.  The  higher 
branches  are  always  provided  with  prehensile  organs  for  seiz- 
ing the  food,  which  are  arranged  in  pairs. 

360.  These  are  best  seen  in  the  Lobster,  where  they  are 
enormously  developed,  projecting  in  front  of  the  eyes  a dis- 
tance nearly  equal  to  that  of  the  length  of  the  whole  body, 
and  each  extremity  is  furnished  with  a powerful  pair  of  pincers. 
Some  of  the  higher  Crustaceans  have  a sort  of  horny  teeth 
implanted  in  the  coats  of  the  stomach  which  are  worked  by  a 


359.  What  are  the  jaws  of  crustaceans? 


AND  PHYSIOLOGY. 


197 


Fig.  200. 


Digestive  Organs  of  Ammotlica  pycnogonoides  (Crustacean),  a.  Esophagur  h.  Stom« 
ach.  c.  Intestine,  d.  Digestive  Cavity  of  the  Jaws.  e.  Digestive  Cavity  of  the  Legs. 

powerful  set  of  muscles,  which  help  in  the  reduction  of  the 
food.  These  teeth  are  found  in  the  Lobster’s  stomach.  The 
stomach  of  the  Leech  is  very  capacious,  being  nearly  the  size 
of  the  whole  body.  The  same  is  essentially  true  of  the  com- 
mon Earthworm,  which  is  an  Annelid.  In  many  insects 
salivary  glands  are  present,  and  in  such  cases  they  are  placed 
at  the  commencement  of  the  alimentary  canal.  The  different 
parts  of  the  alimentary  canal  in  insects  ^‘may  be  properly 
distinguished  in  the  following  manner.  The  first  portion  is 
the  Esophagus,  muscular,  occupying  the  three  thoracic  seg- 
ments and  often  dilated  at  its  posterior  part  into  a crop 
(Ingluvies)  and  muscular  gizzard  (Proventriculus).  Some- 
times there  is  appended  to  the  Esophagus  a sucking  stomach, 


198 


HITCHCOCK’S  ANATOMY 


Fia.  201. 


Aplysia  (Mollusc)  laid  open  to  show  the  viscera,  a.  Esophagus,  c.  Salivary  Glands. 
^/.  Cephalic  Ganglion,  e.  Esoidiageal  Ganglion,  First  Stomach  or  Crop.  A.  Third 

or  Tnio  Stomach,  i.  (Jizzard.  Jc.  Intestine.  Liver,  Posterior  Ganglion,  w.  Aorta. 
o.  Hepatic  Artery.  7?.  Ventricle  of  Heart,  q.  Auricle,  n a.  Branchiae  or  Gills,  v. 
Lower  Intestines,  v.  Ovary. 


AND  PHYSIOLOGY. 


199 


consisting  of  a more  or  less  pedunculated  thin  walled  vesicle, 
which  is  multiplicated  on  itself  when  empty.  The  second 
portion  consists  of  a stomach  (ventriculus)  in  which  the  chyle 
is  formed,  and  which  is  continuous  at  the  point  of  insertion 
of  the  malpighian  vessels  with  the  third  portion  of  the  digest- 
ive canal.  This  third  portion  commences  by  a small  and  usu- 
ally short  ileum,  which  is  followed  by  a colon  larger  and  of 
variable  length.  This  last  often  has  a caecum  at  its  anterior 
extremity,  and  terminates  posteriorly  in  a short,  muscular 
Rectum.'^ 

considerable  number  of  insects  take  no  food  during 
their  perfect  state,  the  object  of  their  existence  being  only  to 
accomplish  the  act  of  reproduction.  Their  jaws  are  often 
very  rudimentary,  and  are  fit  neither  for  sucking  nor  for 
masticating.’’ 

361.  The  Annelida  have  sometimes  quite  complicated 
jaws,  even  as  many  as  eight  or  nine,  moving  laterally.  They 
have  also  salivary  and  hepatic  glands,  as  have  many  other 
invertebrates.  These  are  shown  on  Fig.  197,  which  repre- 
sents the  whole  alimentary  canal  of  an  insect. 

362.  The  Cephalopod  Mollnscs  have  a mouth,  two  horny 
jaws  moving  vertically  in  the  pharynx,  a tongue,  an  oeso- 
phagus, a stomach,  a pylorus,  and  an  intestinal  canal. 

363.  In  the  Cephalophora  the  jaws  move  laterally  for  the 
most  part.  In  the  whole  class  we  find  a biliary  apparatus 
and  generally  salivary  glands.  Fig.  201  shows  the  digestive 
organs  of  a Gasteropod,  the  Aplysia.  Nearly  all  the  Ceph- 
alophora have  a longer  or  shorter  fleshy  mass  attached  to 
the  base  of  the  pharynx  that  is  comparable  to  a tongue.  It 
has  a longitudinal  grove  in  it,  and  is  sometimes  included  in  a 
sheath.  It  is  always  covered  with  horny  denticulated  plates 
and  spines,  which  are  very  delicate,  and  arranged  in  quite 
elegant  longitudinal  and  transverse  rows.  The  points  of  these 
spines  turn  backward,  which  aids  greatly  in  swallowing. 


200 


HITCHCOCK’S  ANATOMY 


3G4.  In  some  families  of  the  Eiitozoa — the  Cyslici,  the 
Cestoclcs  and  A c a ii  t li  o c e p li  a I i — there  is  no  mouth  nor  pro{)cr 
intestinal  canal,  but  there  are  vessels  for  the  circulation  of 
nourishment  which  is  received  directly  through  the  sides  of 
the  body,  on  the  principle  of  endosmosis. 


CHAPTER  FOURTH. 


THE  CIRCULATING  SYSTEM.— ANGIOLOGY,  OR  HISTORY  OF 
THE  ORGANS  OF  BLOOD  CIRCULATION. 


DEFINITIONS  AND  DESCRIP  T^ONS. 


365.  The  Circulatory  Organs. 


this  system  are  the  Heart, 
Arteries,  Veins,  and  Capil- 
laries, and  are  mainly  tubes 
of  various  diameters  and  a 
hollow  organ,  with  the  double 
office  of  receiving  and  propel- 
ling the  blood. 

366.  The  Heart.  — The 
Heart,  or  central  engine  of 
circulation,  is  located  in  the 
thorax  or  chest,  resting  by  its 
lower  surface  on  the  dia- 
phragm, and  somewhat  to  the 
left  of  the  middle  line  of  the 
body.  It  is  of  a conical  form, 
made  of  animal  muscular  fiber, 
the  fibers  crossing  themselves 
in  at  least  three  directions ; 
and  it  is  a sin2;ular  fact  that 


•The  organs  composing 
Fig.  202. 


An  Anterior  view  of  the  Heart  in  a Ver- 
tical Position,  with  its  Vessels  injected.  1, 
Eight  Auricle.  2,  Left  Auricle.  3,  Eight 
Ventricle.  4,  Left  Ventricle.  5,  Descend- 
ing Vena  Cava.  6,  Aorta.  7,  Left  Pulmo- 
nary Artery.  8,  The  Arteria  Innominata. 
9,  Left  Primitive  Carotid.  10,  Left  Sub- 
Clavian  Artery.  11,  Anterior  Cardiac  Ves- 
sels in  the  Vertical  Fissure.  12,  Posterior 
Vessels  from  the  Transverse  Fissure.  13, 
Main  Trunk  of  the  Pulmonary  Artery. 


365.  What  are  the  organs  used  for  the  circulation  of  the  blood  ? 366.  Give  the  location 
of  the  Heart. 


202 


HITCHCOCK’S  A N A T O Y 


many  of  the  fibers  of  the  heart 
anastomose,  or  join  ^vith  each 
other  in  many  places,  as  is 
seen  in  Fig.  203.  The  heart 
is  a double  organ,  one  side 
being  called  the  arterial  and 
the  other  the  venous,  or  left 
and  right  hearts,  since  the  for- 
mer receives  and  propels  the 
pure  or  arterial  blood,  while 

Anastomosing  Fibers  of  the  Human  Heart.  the  latter  cirCulatCS  VenOUS 

blood.  Again,  each  of  the  two  sides  or  hearts  are  divided 
into  an  auricle  and  a ventricle.  Each  of  these  four  cavities 
will  ordinarily  contain  about  three  fluid  ounces,  making  the 
whole  heart  to  contain  nearly  a pint. 

367.  The  Auricles  and  Veiilriclcs.— The  Auricles  are 
the  uppermost  cavities  of  the  heart,  and  are  somewhat  smaller 

Fig.  204. 

Xij  ao  t ac  vj 

Artery  of 
the  Arm. 

Vein  of 
the  Arm. 


Left  Lung. 


od  VC  vd  a vg 

Lungs,  Heart,  and  Principal  Vessels  in  Man.  or7,  Eight  Auricle,  vd^  Eight  Ventricle. 
vg^  Left  Ventricle,  a,  Aorta,  ac,  Carotid  Arteries.  vc\  Vena  Cava,  t,  Trachea,  -rj. 
Jugular  Veins. 

What  are  its  shape,  size,  and  four  cavities  called?  What  is  the  capacity  of  an  adult 
heart  ? 


AND  PHYSIOLOGY. 


203 


than  the  Ventricles,  or  lower  ones.  The  auricles  also  have 
the  thinnest  walls,  and  are  capable  of  considerable  dilatation, 
since  by  a sudden  effort  of  the  body  the  blood  is  liable  to  be 
sent  in  great  quantities  to  the  heart,  and  the  veins  would  be 
in  danger  of  rupture  were  there  no  elasticity  in  the  receptacle. 
The  thickened  walls  of  the  venti  icles  give  increased  power  of 

Fig.  205. 

Vena  Cava  Sup.  Art.  Pulm.  Aorta.  Art.  Pulm. 


Pulmonary  Veins. 

Eight  Auricle.  • — 

Tricuspid  Valve.  ** — 

V ena  Cava  Inferior.  

/ 

Eight  Ventricle.  ** 

i i , 

Septum.  Aorta. 

Theoretical  Section  of  the  Heart  in  Man. 

contraction.  This  is  needed  because  the  ventricles  drive  the 
blood  from  the  heart,  and  the  auricles  receive  it  on  its  return. 
The  right  ventricle,  however,  propels  the  blood  only  to  the 
lungs,  while  the  left  ventricle  sends  it  to  all  parts  of  the  body 
except  the  lungs.  The  left  auricle  receives  only  the  blood 
from  the  lungs,  while  the  right  auricle  receives  it  from  all  the 
other  parts  of  the  body. 

368.  Valves  of  the  Heart. — Between  the  auricles  and  ven- 
tricles are  peculiar  forms  of  muscular  and  tendinous  fibers, 
resembling  cords  and  pillars,  that  are  termed  valves,  making 
a sort  of  curtain  to  allow  the  flow  of  blood  from  the  auricles 
to  the  ventricles,  but  not  in  the  opposite  direction.  At  the 

36T.  Give  the  essential  differences  between  the  auricles  and  ventricles.  Why  does  the 
left  ventricle  need  the  thickest  walls  ? 868.  Describe  the  valves  which  lie  between  the 
auricles  and  ventricles. 


204 


II I T c n c o c i: ’ s a n a t o ?.r  y 


point  where  the  arterie3  arc  given  ofT 
from  each  ventricle  are  found  (in  each) 
three  crescent-shaped  folds  of  semi- 
cartilaginous  tissue  called  Semi-lunar 
Valves,  to  allow  the  motion  of  blood  in 
an  outward  direction,  but  to  prevent 
the  return,  which  is  called  regurgita- 
tion. 

369.  Pericardium. — In  addition  to 
the  fasciae  and  fatty  matter  which  im- 
mediately invest  the  heart,  this  organ  is  enclosed  in  another  mem- 
brane in  the  form  of  a shut  sac,  a fibro-serous  membrane  called 


Fig.  207. 


Semi-lunar  Valves  of  the  Aorta  laid  open,  a,  Corpus  Arantii  on  the  Free  Border.  &, 
Attached  Border,  c,  Orifices  of  Coronary  Arteries. 

the  Pericardium  (meaning  about  the  heart).  This  contains  a 
small  quantity  of  a fluid  like  water,  so  that  the  heart  actually 
floats  in  a liquid,  and  does  not  rest  firmly  upon  any  hard  sur- 
face. The  pericardium  not  only  exists  as  a loose  sac  about 
the  heart,  but  it  is  reflected  upon  it  where  the  vessels  are 
given  off ; covering  it  in  the  same  manner  as  the  fasciae  cover 
and  protect  the  muscles. 

370.  Arteries — Their  Coats. — The  Arteries  are  tough  and 
cylindrical  tubes  which  convey  the  blood  from  the  heart  to  the 
different  parts  of  the  body.  They  are  made  up  of  three  mem- 


Describo  the  Sorni-lunar  V:ilvos  find  their  locntion.  8G9.  What  is  the  sac  called  that 
surrounds  the  heart ? What  fluid  docs  it  contain?  llow  much  of  it  is  there?  Is  the 
jiericardium  attached  at  all  to  the  heart?  870.  Of  how  many  coats  arc  the  arteries  com- 
posed ? 


Fig.  206. 


Semi-lunar  Valves  of  the 
Heart  closed. 


AND  rilYSIOLOGY. 
Fia.  208. 


205 


Temporal 

Artery. 


Art. 

Pediosa. 


Vertebral 

Artery. 

Subclavian 

Artery. 


Peroneal 

Artery. 


Arterial  System  in  Man. 


branes,  of  'which  the  middle  one  deserves  especial  attention. 
This  is  an  elastic  coat  composed  of  yellow  fibrous  tissue  (Fig. 
209),  in  order,  as  we  shall  presently  see,  to  aid  in  the  circu- 


Describe  each  one  and  tbeir  peculiar  value. 


20G 


HITCHCOCK’S  ANATOMY 


lation  of  tho  blood. 
The  inner  one  is  smooth 
and  of  a serous  charac- 
ter, for  the  ready  pas- 
sage of  tho  blood  over 
it.  The  arteries  (all 
above  ^V^h  inch  in 
diameter)  are  nourished 
by  a capillary  net-work 
which  is  made  from  ad- 
joining blood-vessels.  Nerves  are  distributed  to  some  arteries, 
but  ordinarily  they  only  accompany-  them. 

371.  The  Aorta. — The  arteries  sent  to  every  portion  of 
the  body  from  the  left  ventricle  proceed  from  one  trunk, 
called  the  Aorta,  meaning  a starting-point.  It  is  nearly  an 
inch  in  diameter,  and  ascends  in  a perpendicular  direction 
for  about  two  inches,  when  it  makes  a curve  upon  itself,  and 
descends  through  the  thorax  and  abdomen  until  it  reaches 
the  fourth  lumbar  vertebra,  when,  as  is  the  case  with  most 
of  the  large  arteries,  it  divides  into  two  branches  of  equal 
size.  Between  the  curve  or  arch  of  the  aorta  and  the  heart 
no  branches  are  given  off,  but  from  the  summit  of  this  arch 
to  the  subdivision  in  the  abdomen  a great  number  of  branches 
are  distributed  to  the  different  portions  of  the  chest  and  ab- 
domen. 

372.  Description  of  Particular  Arteries — Innominata 
— Carotid — Subclavian — Axi Ilary — Brachial — Ulnar  Ra- 
dial— Palmar  Arch. — The  first  branch  arising  from  the  sum- 
mit of  the  aortic  arch  is  the  large  one  called  the  Innomi- 
nata, or  nameless  artery.  Next  comes  the  Carotid,  and  both 
distribute  themselves  to  the  head  and  upper  extremities. 


Fig.  209. 


Highly  Magnified  Portion  of  the  Middle  Coat  of 
the  Arteries. 


871.  Wliat  is  the  Aorta?  . Wliat  docs  tho  word  aorta  mean?  Give  its  course  till  it 
subdivides.  Where  does  it  divide  into  tho  common  iliacs?  872.  Where  are  tho  In- 
nominata Arteries?  Tho  Carotid? 


AND  PHYSIOLOGY. 


207 


Fia.  210. 


A View  of  the  Heart,  with  the  Great  Vessels  of  the  Neck  in  Situ.  1,  Eight  Ventricle 
of  the  Heart.  2,  Right  Auricle.  8,  Left  Ventricle.  4,  Left  Auricle.  5,  Pulmonary 
Artery.  6,  Arch  of  the  Aorta.  7,  Descending  Vena  Cava  at  its  entrance  into  the  Eight 
Auricle.  8,  Ascending  Vena  Cava.  9,  Thoracic  Aorta.  10,  Arteria  Innominata.  11, 
Eight  Brachio-Cephalic  Vein.  12,  Left  Brachio-Cephalic  Vein.  13.  Section  of  the  Sub- 
Clavian  Artery.  14,  Section  of  the  Siib-Clavian  Vein.  15,  15,  Primitive  Carotid  Ar- 
teries. 16,  16,  Internal  Jugular  Veins.  17,  17,  External  Jugular  Veins.  Between 
these  Veins  is  seen  the  Section  of  the  Sterno-Cleido-Mastoid  Muscle.  18,  The  Trunk 
formed  by  the  Superficial  Cervical  Veins,  known  sometimes  as  the  Anterior  Jugular 
Vein.  19,  A Branch  from  it  to  the  Facial.  20,  Main  Trunk  from  the  Inferior  Thy- 
roid Veins.  21,  Superior  Thyroid  Vein.  22,  Transverse  Cervical  Artery  and  Vein. 
23,  Lingual  Artery  and  Vein.  24,  Facial  Artery  and  Vein. 

The  Innominata  on  the  right  very  soon  becomes  the  Sub- 
clavian, after  which  the  corresponding  arteries  of  both  arms 
receive  the  same  name.  The  Sub-clavian  Artery,  as  its  ety- 
mology  implies,  lies  directly  beneath  the  clavicle  until  it 
reaches  the  axilla,  or  arm-pit,  where  it  receives  the  name  of 


The  Sub-clavian  ? The  Axillary  ? 


208 


II  I T C II<;  O C K ’ S A N A T O Y 


r 


Fia.  211. 


A Yiew  of  the  Arteries  of  the  Neck  and  Shoulder.  1,  Primitive  Carotid  Artery.  2, 
Internal  Carotid  Artery.  8,  External  Carotid  Artery.  4,  The  Superior  Thyroid  Artery. 
5,  Branches  to  the  Muscles.  6,  Main  Branch  to  the  Gland.  7,  Inferior  Pharyngeal  Ar- 
tery. 8,  Lingual  Artery.  1),  Facial  Artery.  10,  Its  Branches  to  the  Sub-Maxillary  Gland. 
11,  Sub-Mental  Branch.  12,  Principal  Branch  of  the  Facial  as  it  goes  over  tlic  Jaw. 
13,  Occipital  Artery.  14,  Branches  to  the  Muscles  on  the  Back  of  the  Neck.  15,  Main 
Trunk  to  the  Occiput.  16,  Posterior  Auricular  Artery.  17,  A Branch  cut  otf,  which 
goes  to  the  Parotid  Gland.  IS,  Origin  of  the  Internal  Maxillary  Artery.  19,  Origin  of 
the  Temporal  Artery.  20,  Origin  of  the  Anterior  Auricular.  21,  The  Sub-CIavian.  22, 
Origin  of  the  Internal  Mammary.  23,  Trunk  of  the  Inferior  Tliyroid,  from  which  arise 
in  this  subject  the  Anterior  and  Posterior  Cervical  Arteries.  24,  Branch  of  the  Inferior 
Thyroid  going  to  the  Thyroid  Gland.  25,  Anterior  Cervical  going  up  the  Neck.  26, 
Posterior  or  Transverse  Cervical.  27,  Branches  to  the  Scaleni  and  Levator  Scapulaa 
Muscles.  28,  The  Superior  Scapular  Artery.  29,  The  Thoracica  Superior  of  the  Axil- 
lary Artery.  30,  A Branch  to  the  Deltoid.  81,  Eecurrent  Branches  of  the  Intercostals. 

Axillary  Artery.  Then  as  it  passes  along  the  inner  side  of 
the  humerus  it  is  called  the  Brachial,  until  it  has  passed  be- 
yond the  inner  side  of  the  elboAV,  where  it  is  divided  into  the 
Ulnar  and  lladial,  corresponding  in  position  and  direction  to 


Where  are  the  Brachial,  Ulnar,  and  lladial  Arteries  ? 


AND  PHYSIOLOGY. 


209 


the  ulna  and  radius.  Some- 
times, however,  the  branch- 
ing takes  place  higher  up,  as 
is  seen  in  cut  212.  When 
these  have  fairly  passed  the 
wrist,  they  both  join  again  in 
an  artery  which  describes  a 
curve  at  the  base  of  the  meta- 
carpus crossing  the  palm  of 
the  hand,  and  called  the  Pal- 
mar Arch.  Small  branches 
are  given  off  from  this  which 
supply  the  different  parts  of 
the  hand,  including  the  fin- 
gers and  thumb. 

373.  Distribution  of  the 
Carotids — Vertebral — Circle 
of  Willis. — The  common  Ca- 
rotid Arteries,  one  on  each 
side  of  the  neck,  pass  upwards 
from  the  innominata  and  sub- 
clavian nearly  as  far  as  the 
angle  of  the  jaw,  when  they 
divide  into  the  internal  and 
external  carotids,  the  latter 
furnishing  blood  to  the  face, 
and  the  former  to  the  brain  and 
back  part  of  the  head.  The 
Vertebral  Artery  is  also  giv- 
en off  from  the  sub-clavian, 
which,  passing  backward,  en- 
ters the  spinal  column  at  the 
sixth  cervical  vertebra,  and 

Deep-Seated  Palmar  Arch. 


Fig.  212. 


Arteries  of  the  Arm.  1,  Termination  of 
the  Axillary  Artery.  2,  The  Brachial  Ar- 
tery. 3,  3,  Radial  Artery,  4,  4,  Ulnar  Ar- 
tery. 5,  A Recurrent  Branch.  6,  Anterior 
Interosseous  Artery.  7,  Superficial  Pal- 
mar Arch  formed  by  the  Ulnar  Artery.  8, 
9,  The  Anastomosis  of  the  two  Arteries,  much  enlarged. 


What  is  the  Palmar  Arch  ? 373.  Give  the  branches  of  the  Carotid  as  it  passes  up- 
ward to  the  head. 


P (B 


210 


HITCHCOCK’S  ANATOMY 


passing  through  a foramen  or  opening  in  the  transverse  process 
of  each  of  these  vertebrae,  at  last  reaches  the  posterior  portion 
of  the  brain.  This  artery  in  the  brain  meets  with  the  termi- 
nal branches  of  the  internal  carotid,  so  that  the  blood  can 
easily  reach  the  brain  from  either  direction.  By  this  ar- 
rangement, if,  from  pressure  or  accident,  the  flow  of  blood 
to  the  brain  in  either  of  these  channels  should  be  obstructed, 
the  other  would  supply  it;  for  sensation  and  consciousness 


Fig.  213. 


Circle  of  Willis.  1,  Vertebral  Arteries.  2,  3,  Anterior  and  Posterior  Spinal  Arteries. 
4,  Posterior  Meningeal  Artery.  5,  Inferior  Cerebellar.  6,  Basilar.  7,  Superior  Cerebel- 
lar. 8,  Posterior  Cerebral.  9,  Branch  of  Carotid.  10,  Internal  Carotid.  11,  Ophthalmic 
Artery.  12,13,  Cerebral  Arteries.  14,  Anterior  Communicating  Artery. 

entirely  cease  if  the  brain  be  deprived  of  its  arterial  blood. 
This  arrangement  is  called  the  “ Circle  of  Willis’’  from  its 
discoverer. 

What  arteries  does  the  Vertebral  communicate  with  iu  the  brain?  What  is  the  ser- 
vice of  this  arrangement? 


AND  PHYSIOLOGY. 


211 


874.  Thoracic  Aorta— Abdominal  Aorta — Coeliac  Axis — 
Gastric,  Hepatic,  Splenic,  Renal,  Mesenteric,  and  lum- 
bar Arteries. — After  the  aorta  fairly  commences  its  descent 
— called  the  Thoracic  Aorta — several  small  branches  are  given 
oflf  from  it  which  send  nourishment  to  the  heart  and  lungs,  and 
next  a pair  which  are  distributed  to  the  diaphragm.  Then 

Fig.  214.  ^ / 


A View  of  the  Abdominal  Aorta  and  its  Branches.  1, 1,  The  Diaphragm.  2,  Foramen 
Quadratum  and  Section  of  the  Ascending  Vena  Cava.  3,  Foramen  Esophageum  and 
Section  of  the  Esophagus.  4.  Foramen  Aorticnm  in  the  Crura  of  the  Diaphragm.  The 
Phrenic  arteries  are  seen  going  to  the  Diaphragm.  5,  CapsulsE  Eenales.  6,  The  Kid- 
neys. 7,  Abdominal  Aorta.  8,  Phrenic  Arteries.  9,  Ccelic — giving  off.  10,  The  Sple- 
nic. 11,  The  Gastric.  12,  The  Hepatic.  13,  Section  of  Superior  Mesenteric.  14,  Emul- 
gent  Arteries.  15.  Spermatic  Arteries.  16,  Inferior  Mesenteric.  17, 17,  Lumbar  Arteries. 
18,  Division  of  the  Abdominal  Aorta.  19,  Its  last  Branch — the  Middle  Sacral.  20, 
Primitive  Iliacs.  21,  Ureters — in  their  Position  to  the  Arteries.  22,  Internal  Iliacs. 
23,  External  Iliacs.  24,  Circurnflexa  II ii.  25,  Distribution  of  the  Epigastric.  26,  Blad- 
der distended  with  Urine.  The  Vesical  Arteries  are  seen  near  it. 


374.  What  are  the  first  branches  of  the  Thoracic  Aorta  ? 


212 


HITCHCOCK’S  ANATO:\IY 


Fm.  215. 


A Front  View  of  the  Femoral  Artery,  as 
irell  as  of  the  External  and  Primitive 


we  meet  with  a large  trunk 
given  off  just  below  the  dia- 
phragm, about  half  an  inch 
in  length,  called  the  Coeliac 
Axis,  which  gives  origin  to 
the  Gastric  artery  supplying 
the  stomach,  the  Hepatic, 
running  to  the  liver,  and  the 
Splenic  furnishing  blood  for 
the  spleen.  Below  this  we 
find  the  Renal  arteries,  sup- 
plying the  kidneys,  and  the 
Superior  and  Inferior  Mesen- 
teric Arteries,  wdiich  give 
blood  to  the  intest’nes,  and  the 
Lumbar  Arteries,  terminating 
in  the  external  muscles  of  the 
abdomen. 

375.  Iliac  Arteries — Fe- 
moral, Popliteal,  and  Tib- 
ial  Arteries— Dorsalis  Pe- 
dis.— As  already  mentioned, 
the  aorta  divides  into  two 
branches  opposite  the  fourth 
lumbar  vertebra,  for  the 
supply  of  the  lower  extrem- 


IliacsofthePwiglit  Side.  1,  Primitive  Iliac  Artery.  2,  Internal  Iliac  Artery.  3,  Exter- 
nal Iliac  Artery.  4,  Epigastric  Artery.  5,  Circumflexa  Ilii  Artery.  6,  Arteria  Ad  Cu- 
tern  Abdominis,  7,  Commencement  of  the  Femoral  just  under  the  Crural  Arch.  8, 
Point  where  it  passes  the  Vastus  Internus  Muscle.  9,  Point  where  it  leaves  the  Front 
of  the  Thigh  to  become  Popliteal.  10,  Muscular  Branch  to  the  Psoas  and  Iliacus.  11, 
External  Pu.lic  Artery  cut  olf.  12,  Origin  of  the  Internal  Circumflex.  13,  Profunda  Fc- 
moris.  1 1.  Muscular  Branch.  15,  16,  Artery  to  the  Vastus  Externus  Muscle.  17,  Artery 
to  tlio  Pcctincus  and  Adductors.  18,  First  Perforating  Artery.  19,  19,  Muscular  Ar- 
teries. 20,  21,  Anastomotica.  22,  Superior  External  Articular.  28,  Middle  Articular. 
24,  Inferior  External  Articular.  25,  Inferior  Internal  Articular. 


Describe  the  Coeliac  Axis.  Where  are  the  Gastric,  Hepatic,  Splenic,  Penal,  and  Lum- 
bar Arteries  ? 


AND  PHYSIOLOGY. 


ities.  These  are  the  com- 
mon iliacs,  from  being  near 
the  ilium,  and  each  of  them 
soon  subdivides  into  the  Ex- 
ternal and  Internal  Iliac,  the 
former  of  which  supplies  the 
greater  portion  of  the  leg 
with  blood.  As  soon  as  it 
passes  over  the  pubis  it  be- 
comes the  Femoral  Arterj, 
which  at  first  is  quite  exter- 
nal, lying  just  beneath  the 
skin  and  upon  the  pubis  ; but 
as  it  passes  down  the  femur  it 
plunges  deeper  and  deeper  into 
the  soft  parts  until  it  appears 
behind  the  knee,  where  it  re- 
ceives the  name  of  the  Pop- 
liteal Artery.  This  is  only  a 
few  inches  in  length,  and  at 
the  upper  extremity  of  the 
tibia  divides  into  the  Anterior 
and  Posterior  Tibial  Arteries. 
The  former  runs  along  the 
inner  side  of  the  tibia  and 
over  the  tarsal  bones,  until  it 
reaches  the  metatarsus,  when 
it  becomes  the  Dorsalis  Pedis, 
which  gives  off  branches  to 


Fig.  216. 


A View  of  the  Arteries  on  the  Back  of 
the  Leg.  The  Muscles  have  been  removed 
so  as  to  display  the  Vessels  in  their  whole 
length.  1,  The  Popliteal  Artery,  cut  olf 
so  as  to  show  the  Articular  Arteries.  2» 
Lower  End  of  the  same  Artery  on  the  Popliteus  Muscle.  3,  Point  of  Bifurcation  into  the 
Posterior  Tibial  and  Peroneal.  4,  Superior  Internal  Articular  Artery.  5,  Superior  Ex- 
ternal Articular  Artery.  6,  Middle  Articular  Artery.  7,  Inferior  Internal  Articular  Ar- 
tery. 8,  Inferior  External  Articular  Artery.  9,  Branch  to  the  Head  of  the  Soleus  Mus- 
cle. 10,  Origin  of  the  Anterior  Tibial  Artery.  11,  Origin  of  the  Posterior  Tibial  Artery. 
12,  Point  where  it  passes  behind  the  Annular  Ligament  to  become  the  Plantar.  13, 14, 
15,  Muscular  Branches.  16,  Origin  of  the  Peroneal  Artery.  17,  17,  Muscular  Branches. 
IS,  IS,  Anastomosis  of  the  Posterior  Tibial  and  Peroneal  Arteries  near  the  Heel.  19, 
Muscular  Branch  from  the  Anterior  Tibial. 


B75.  What  do  tho  common  Iliac  Arteries  become  as  soon  as  they  cross  the- pubis? 
Give  the  location  of  the  Femoral,  Popliteal,  Tibial,  and  Dorsalis  Pedis  Artery. 


214 


HITCHCOCK’S  ANATOlSfY 


each  of  the  toes,  and  suj)plies  the  upper  part  of  the  foot  with 
blood.  The  Posterior  Tibial  Artery  follows  upon  the  back 
side  of  the  leg  a corresponding  course  to  the  anterior  tibial, 
and  supplies  the  sole  of  the  foot  and  toes  with  blood. 

376.  Capillaries. — The  arteries  just  described  area  few 
only  of  the  principal  ones,  since  at  nearly  every  inch  of  their 
course  larger  or  smaller  vessels  are  given  off  according  to  the 


Fig.  211. 


Varieties  of  Capillaries.  A,  Tlioso  around  Fat  Cells,  b,  In  Muscle,  c,  In  Mucous 
Membrane,  d,  Skin  of  Finger. 


nature  of  the  part  to  be  supplied  with  blood,  and,  with  a few 
exceptions,  such  as  the  one  in  the  head  (circle  of  Willis), 
they  all  terminate  in  minute  vessels  called  Capillaries. 

377.  Diameter  of  Capillaries — Functions  Performed 
in  them. — These  are  minute  tubes  j^oth  to  ^oVoth  of  an 
inch  in  diameter,  and  are  always  the  terminations  of  arteries. 
Tlicy  arc  of  a uniform  size,  and  very  regular  in  the  distribu- 


J37G.  How  do  nearly  iiil  tlio  arteries  terminate?  Where  is  the  only  exception  ? 877, 
Btuto  the  diameter  of  the  Capillaries.  What  of  their  uniformity  ? 


AND  PHYSIOLOGY. 


215 


Fig.  218. 


A Front  View  of  the  relative  Positions  of  the  Veins  anrl  Arteries  of  the  Face  and  Neck. 
On  the  Right  side  the  Superficial  Vessels  are  seen,  and  the  Deep-seated  ones  on  the  Left. 
1,  Primitive  Carotid  Arteries.  2,  Superior  Thjuoid  Arteries.  8,  Internal  Jugular  Veins. 
4,  External  Jugular  Veins.  5,  A Branch  known  as  the  Anterior  Jugular  Vein.  6,  Supe- 
perior  Thyroid  Veins.  T,  Facial  Arteries.  8,  Facial  Veins.  9,  Zygomatic  Branch  of  the 
Facial  Artery.  10,  Nasal  Branch  of  the  Facial  Vein.  11,  Anastomosis  of  the  Facial 
Artery  and  Vein  with  the  Ophthalmic  Artery.  12,  Venous  Arch  above  the  Nose.  13, 
Frontal  Vein.  14,  Temporal  Vein.  15,  Temporal  Artery.  16,  Frontal  Branches  of 
the  Temporal  Artery  and  Vein.  17,  Infra-Orbitar  Vessels.  18,  Sub-Aponeurotic  Branch 
of  the  Temporal  Vein.  19,  20,  Venous  Anastomosis  around  the  Eye-Lids.  21,  Frontal 
Branches  of  the  Ophthalmic  Vessels  of  Willis. 

10 


21G 


ir  I T C II  C O C K ’ S A N A T O Af  Y 


Fig,  219, 


tion  of  their  branches,  without  any  increase  in  tlicir  diam- 
eter. The  only  exception  to  this  is  where  red  blood  is  not  re- 
quired for  the  nourishment  of 
the  parts ; as  in  the  white  of 
the  eye,  the  finger  nails,  the 
tendons,  etc.,  where  the  ca- 
pillaries arc  too  small  to  allow 
the  corpuscles  of  blood  to  pass 
througli  them.  And  yet  in 
many  of  the  capillaries  we  find 
their  size  to  be  so  small  that 
the  corpuscles  could  not,  if 
unyielding,  pass  through. 
But  this  is  readily  accom- 
plished in  most  cases  by  the 
flexibility  of  the  corpuscle, 
which  permits  itself  to  bo 
doubled  up  to  such  an  extent 
that  it  will  easily  pass  through 
a tube  much  smaller  than  its 
normal  diameter.  In  the  ca- 
pillaries the  important  pro- 
cesses of  secretion,  nutrition, 
and  the  production  of  a por- 
tion of  animal  heat  take  place  ; 
so  that  there  is  no  place  in 
the  whole  body  ex(3ept  the 

A View  of  the  Veins  of  the  Trunk  and  outer  COat  of  the  eye,  the  ten- 

The  Left  Vena  Innorninata.  8,  The  Riirht  donS,  the  nails,  and  whlte 
Vena  Innoininata.  4,  The  Ri^iht  Buh-Cla-  portions  of  the  bodv  gencr- 
vian  Vein.  5,  The  Internal  Jugular  Vein.  ^ ^ , 

6,  The  External  Jui^ular.  7,  The  Anterior  ttHy  wllCre  true  CapillariCS  are 
Jisular  8 Tl.c  Intoior  Vona  Cuva.  9 ^Ot  found. 

The  External  Iliac  Venn.  10,  The  Internal 
Iliac  Vein.  11,  The  I’riniitivc  Iliac  Veins. 

12,  12,  Lurnhar  Veins.  18,  The  Ki;,dit  Spermatic  Vein.  14,  The  Left  Spermatic  Vein. 
15,  The  liiirht  Emnlixent  Vein.  10,  The  Trunk  of  the  Hepatic  Veins.  17,  The  Vena  Azy- 
pos.  18,  The  llemi-Azypns.  10,  A Uraneli  communicatimr  with  the  Left  Renal  Vein. 
20,  The  Termination  of  the  llemi-Azypos  in  the  Vena  Azygos.  21,  The  Superior  Inter- 
Costal  Vein. 


Where  are  true  eapillaric.s  not  found?  What  takes  place  in  them? 


AND  PHYSIOLOGY. 


217 


Fig.  220. 


878.  The  Veins — Their  Coats— Their  Yoliime, — The  Veins 
carry  the  blood  from  all  parts  of  the  body  to  the  heart.  Like 
the  arteries,  they  have  three  coats,  and  the  larger  veins  follow 
the  same  general  course  as  the  large  arteries.  The  sm.aller 
veins,  however,  are  much  more  numerous  than  the  smaller  ar- 
teries, and  are  most  abundant  just  beneath  the  skin.  The 
whole  volume  of  the  veins  may  be  regarded  as  a large  cone, 
with  the  base  at  the  surface  of  the  body  nnd  the  apex  at  the 
heart,  so  that  in  these  vessels  the  blood  is  continually  flowing 
faster  and  faster,  in  consequence  of  the  fluid  coming  into  a 
larger  channel  from  small  extremities,  while  the  reverse  hap- 
pens in  the  arteries.  The  veins  are  much  thinner  in  struc- 
ture than  the  arteries,  so  that  after  death  they  most  usually 
collapse.  (See  Fig.  218,  p.  215.) 

379.  location  of  the  larg- 
er Veins — Sinuses. — As  al- 
ready mentioned,  the  larger 
veins  usually  lie  near  the 
larger  arteries.  Both  also 
frequently  have  the  same 
names.  But  there  are  sev- 
eral remarkable  exceptions  to 
this,  as  in  the  vessels  of  the 
brain.  Here  are  but  few 
veins,  but  several  sinuses  or 
channels.  These  are  canals 
excavated  in  the  dura  mater 
of  the  brain  with  this  mem- 
brane for  an  outer  coat,  and 
the  serous  layer  of  the  true 

veins  for  an  inner  coat.  These  sinnses  of  the  Base  of  the  skuii.  i, 
run  in  difierent  directions  on  ophthalmic  Veins  2,  Ca^^^mous  Sinus. 

3,  Circular.  4,  6,  Inferior  Petrosal.  5,  9, 
the  inside  of  the  skull,  and  occipital  Sinuses.  7,  Internal  Jugular 

Vein. 


373.  What  course  does  the  blood  take  in  the  veins  ? Give  the  coa:s  of  the  veins. 
What  is  the  relative  proportion  of  small  veins  and  small  arteries?  What  is  said  of  their 
aggregate  volume?  879.  Where  are  the  larger  veins  usually  found ? What  are  Sinuses, 
and  where  are  they  found  ? 


218 


HITCHCOCK’S  ANATO>rY 


most  of  them  empty  into  the  great  veins  of  the  neck.  Their 
probable  service  is  to  afford  a free  passage  of  blood  from  the 
brain,  even  if  by  excess  of  arterial  action  this  organ  should  bo 
overcharged  with  blood. 

380.  Portal  System — Use  of  tlie  Portal  System. — An- 
other apparent  exception  to  the  ordinary  system  of  veins  is 
seen  in  what  is  called  the  Portal  System.  This  comprises 
those  vessels  which  receive  their  blood  from  the  intestinal 
canal,  the  stomach,  and  the  spleen.  As  these  small  vessels 
unite  into  a larger  trunk,  instead  of  passing  directly  to  the 
heart,  they  form  what  is  called  the  Portal  Vein,  which  emp- 
ties itself  into  the  liver.  This  vein  ramifies  into  every  part 
of  the  liver,  where  the  blood  is  again  collected  by  a series  of 
vessels  which  unite  into  several  trunks,  called  the  Hepatic 
Veins,  and  which  convey  the  blood  to  the  heart.  The  design 
of  this  arrangement  is  not  certainly  known  as  yet,  although 
it  is  probable  that  the  blood  which  returns  from  the  alimentary 
canal  is  not  fitted  to  enter  the  general  circulation  until  it  has 
gone  through  some  change  in  the  liver. 

381.  Origin  of  llie  Vrins 
— Valves — Their  Discoverer. 
— The  Veins  all  take  their  ori- 
gin in  the  capillary  vessels  in 
every  part  of  the  body  except 
those  of  the  stomach,  and  in 
number  and  length  of  tube 
greatly  exceed  the  vessels  of 
the  arterial  system.  In  the 
lining  membrane  of  the  veins, 
also,  w^e  find  a peculiarity 
not  presented  in  the  arteries. 
This  is  the  presence  of  folds, 
so  that  pouches  or  bags  are 
formed,  which  readily  suffer  the  flow  of  blood  tow^ards  the 

Of  whul  especial  stirvic(5  are  they?  880,  Describe  tlie  Portal  System.  What  is  the 
l)robablc  use  of  so  marked  an  exce{)tlon  to  the  c^eneral  circulating  System?  381.  W^here 
do  the  Veins  take  their  origin  ? What  is  said  of  the  Valves  of  the  Veins? 


Tig.  221, 


h - 


Vein  laid  open  to  show  the  Valves. 
Vein,  b,  Valves. 


AND  PHYSIOLOGY. 


219 


heart,  but  almost  entirely  pre- 
vent its  passage  in  an  oppo- 
site direction.  They  act  in 
the  same  manner  as  valves  in 
machinery,  although  with  no 
loss  from  friction,  and  conse- 
quently no  necessity  of  a lu- 
bricating fluid.  It  was  the 
discovery  of  these  valves  in 
the  veins  which  led  Harvey, 
an  English  physician,  to  the 
greater  discovery  of  the  cir- 
culation of  the  blood.  He  in- 
ferred that  the  blood  could 
pass  in  but  one  direction 
through  the  veins,  and  conse- 
quently in  the  opposite  direc- 
tion through  the  arteries. 

382.  Inosculation  — Use 
of  Anastomosis. — The  arter- 
ies and  veins  open  into  each 
other  (i.  e.,  their  own  vessels) 
very  frequently,  allowing  a 
ready  flow  of  blood  from  one 
vessel  to  the  other,  even  if  the 
flow  does  not  happen  to  be  in  the 
most  favorable  direction  from 
the  center  of  circulation  to  the 


The  Superficial  Veins  on  the  Front  of 
the  Upper  Extremity.  1,  Axillary  Artery.  2,  Axillary  Vein.  8,  Basilic  Vein  whore 
it  enters  the  Axillary.  4,  4,  Portion  of  the  Basilic  Vein  which  passes  under  the  Brachial 
Fascia — a portion  of  the  Vein  is  freed  from  the  Fascia.  5,  Point  whe.e  the  Median  Ba- 
silic joins  the  Basilic  Vein.  6,  Points  to  the  Posterior  Basilic  Vein.  8,  Anterior  Basilio 
Vein.  9,  Point  where  the  Cephalic  enters  the  Axillary  Vein.  10,  A portion  of  the  same 
Vein  as  seen  under  the  Fascia ; the  rest  is  freed  from  it.  11,  Point  Avhere  the  Median 
Cephalic  enters  the  Cephalic  Vein.  12,  Lower  portion  of  the  Cephalic  Vein.  13,  Median 
Cephalic  Vein.  14,  Median  Vein.  15,  Anastomosing  Branch  of  the  Deep  and  Superficial 
Veins  of  the  Arm.  16,  Cephalica-Pollicis  Vein.  17,  Sub-Cutaneous  Veins  of  the  Fin- 
gers. 18,  Sub-Cutaneous  Palmar  Veins. 


Who  discovered  the  circulation  of  the  blood? 


220 


HITCHCOCK’S  ANATOMY 


FiOr,  223. 


The  Arteries  and  Deep-seated  Veins  on 
the  Back  of  the  Leg.  1,  Popliteal  Vein. 
2,  Popliteal  Artery.  3,  4,  Vein  and  Artery 
in  their  relative  Position  on  the  Back  of 
tlie  Knee-Joint.  5,  Popliteal  Vein  on  the 
inner  Side  of  the  Joint.  6,  Popliteal  Ar- 
tery without  and  beneath  it.  7,  Extremity 
ofSai)hena  Minor  Vein.  8,  9,  Internal  Ar- 
ticular Vessels,  both  Arteries  and  Veins, 
teries  and  V’'eins.  12,  Junction  of  the  Pero 
ous  Branch  from  the  Anterior  Tibial  Vein. 


extremities.  This  relation  of 
parts  is  called  Inosculation  or 
Anastomosis.  This  arrange- 
ment gives  a plentiful  supply 
of  blood  to  every  part  of  the 
body,  if,  by  wound  or  pressure, 
the  ordinary  channel  of  blood 
to  any  part  should  be  ob- 
structed or  completely  closed 
up.  Inosculation  is  most 
abundant  in  the  veins  and  su- 
perficial arteries,  since  these 
are  most  liable  to  be  thus  im- 
peded. 

383.  The  Blood  — Micro- 
scopic Structure  — Plasma 
or  Serum — Re  d Corpuscles — 
White  Corpuscles — Propor- 
tion of  one  to  the  other. — 
The  blood  of  the  human  sys- 
tem amounts  to  about  eighteen 
pounds,  or  nearly  ten  quarts. 
Is  has  a specific  gravity  a lit- 
tle greater  than  that  of  water, 
is  of  a bright  scarlet  color  if 
drawn  from  an  artery,  or  dark 
purple  if  taken  from  a vein, 
with  a taste  slightly  alkaline, 
and  an  odor  resembling  that 

3,  11,  External  Articular  Vessels,  both  Ar- 
eal and  Posterior  Tibial  Veins.  13,  A Ven- 

14,  A Vein  from  the  Gastrocnemius.  15, 


Anterior  Tibial  Artery  coming  through  the  Interosseous  Ligament.  1C,  Posterior  Tibial 
Artery.  17,  Its  two  Vena)  Coinites.  J8,  Peroneal  Artery.  19,  Its  two  Venae  Comites. 
20,  Vessels  on  the  Heel. 


3S2.  What  is  meant  by  Inosculation  or  Anastotnosis  ? What  is  the  service  of  anasto- 
mosis? In  what  vessels  is  it  luost  abundant  ? 883.  How  much  blood  is  there  in  a hu- 

jnaA  adult?  State  its  color  ami  odor. 


AND  PIIYSIOLOGA". 


221 


of  the  breath  of  the  ani- 
mal from  which  it  is 
taken.  It  penetrates 
every  solid  tissue  of  tie 
system,  as  may  be  known 
by  puncturing  any  part 
of  the  body  with  even  a 
pin,  when  blood  is  sure 
to  follow.  If  it  be  ex- 
amined with  a micro- 
scope when  freshly 
drawn,  it  appears  to  be 
made  up  of  a transparent 
liquid  called  the  Serum 
or  Plasma,  and  a num- 
ber of  minute  circular  bodies,  mostly  of  a red  color,  called 
corpuscles,  or  minute  bodies.  This  fluid  is  found,  on  analy- 
sis, to  be  made  up  of  water,  albumen,  fibrin,  and  several  salts, 
some  of  which  are  found  in  crystals,  as  is  seen  in  the  cut. 
After  it  has  been  drawn  from  the  body  a considerable  time,  it 
separates  into  a thickened  mass  called  Coagulum,  made  up  of 
fibrin  and  the  corpuscles,  while  the 
serum  with  the  albumen  still  remains 
as  a transparent  liquid.  The  Red 
Corpuscles  prove  to  be  flattened  discs 
with  both  surfaces  slightly  concave, 
and  measuring  about  ^^Volh  of  an 
inch  in  diameter,  and  are  in  reality 
nothing  but  a cell,  that  is  a bag  or 
sac  containing  a fluid  composed  of  the 
two  proximate  principles  globuline  and 
hematine.  Besides  the  red  corpuscles,  there  exists  another 
kind  in  the  blood  known  as  the  White  or  Colorless  Corpus- 
cles. They  are  by  no  means  so  abundant,  when  the  body  is 

What  is  its  appearance  under  the  microscoi)e  ? ITow  does  it  conduct  itself  after  stand- 
ing a while  in  an  open  vessel  ? Describe  the  Ee4  Corpuscles.  Describe  the  White  Cor* 
puscles. 


Fig.  225. 
0 ® 


lied  Corpuscles  of  Human 
Blood.  Seen  on  the  Surface, 
c,  Seen  in  Profile,  Seen  in 
a Koll  Magnified  400  Diameters. 


Fig.  224. 


Crystals  from  Human  Blood. 


222 


HITCHCOCK’S  ANATO^NIY 


in  health,  as  the  red  corpuscles.  But  in  certain  diseases,  and 
especially  if  there  ho  a 'wound  in  any  part  of  the  l)ody  to  be 
healed,  the  'white  corpuscles  arc  developed  at  a great  rate, 
although  their  abundance  ceases  when  the  system  is  restored 
to  a sound  state  again.  Their  average  diameter  is  nearly 
3 oVoth  of  an  inch,  and  they  appear  to  be  nucleated  cells.  The 
proportion  of  the  'white  to  the  red  corpuscles  in  health  is  nearly 
as  1 to  346.  The  whole  amount  of  blood  corpuscles  has  been 
estimated  as  high  as  65,570,000,000,000. 

884.  Effect  of  an  Alternate  Exposure  to  Oxygen  and 
Carbonic  Acid . — If  the  red  corpuscles  are  alternately  exposed 
to  oxygen  and  carbonic  acid  they  lose  their  circular  form, 
and  become  corrugated  or  star-shaped,  and  finally  arc  destroyed ; 
and  it  is  calculated  that  millions  of  these  corpuscles  are  de- 
stroyed at  each  pulsation  of  the  heart. 


FUNCTIONS  OF  THE  CIPvCULATORY  SYSTEM. 

385.  The  Main  Use  of  the  Blood-Vessels — The  large 
Angle  made  by  the  Arterial  Branches  near  the  Heart. — 
The  first  and  most  obvious  use  of  the  blood-vessels  is  to  allow 
a free  and  rapid  passage  of  this  fluid  to  every  part  of  the 
body.  This  is  evident  from  the  smooth  lining  of  all  the  ar- 
teries and  veins,  and  from  the  fact  that,  with  the  exception  of 
the  large  arteries  near  the  heart,  the  vessels  branch  off  at  a 
small  angle  from  each  other,  which  arrangement  offers  the 
least  possible  obstruction  to  the  passage  of  the  blood.  In  the 
organs  near  the  heart,  as  the  head  and  lungs,  the  blood  would 
readily  pass  by  smaller  vessels  and  by  less  force  of  the  heart 
in  sufficient  quantity.  But  in  that  case  the  parts  of  the  body 
quite  distant  from  the  center  of  circulation  of  the  blood  would 


When  arc  tlio  wliito  ones  the  most  abundant?  State  the  approximate  number  of  blooc\ 
cor[)U}»cle8  in  one  individual.  SS4.  What  elFeet  lias  an  alternate  exposure  of  oxygen  and 
carbonic  acid  upon  these?  How  many  are  possibly  destroyed  at  each  pulsation  of  tho 
heart  ? 0S5.  Give  tho  use  of  tho  arteries  and  veins. 


AND  PHYSIOLOGY. 


223 


be  imperfectly  supplied.  And  apoplexies  and  congestions 
would  be  much  more  frequent  than  they  now  are  in  the  vital 
organs,  if  the  arteries  did  not  branch  off  at  nearly  a right 
angle. 

886.  Wliy  a large  Amount  of  Arteries  and  Veins. — 
The  necessity  for  such  a large  amount  of  arteries  and  veins, 
and  lh3:r  numerous  connections  with  each  other,  is  evident 
from  the  great  variety  and  extent  of  the  tissues,  and  also 
from  the  great  liability  to  obstruction  from  inflammations,  ac- 
cidents, or  even  the  ordinary  compression  of  clothing.  But 
arranged  as  these  vessels  are  in  the  body,  it  is  a very  difficult 
thing  by  any  mechanical  means  entirely  to  check  the  flow  of 
blood  to  any  part.  But  were  it  not  for  this  system  of  ample 
inosculation  the  amputation  of  a portion  of  the  body  would 
generally  produce  fatal  results. 

387.  Comparative  Capacity  of  tlic  Arteries  and  Veins. 
— If  all  the  arteries  in  the  body  were  to  be  made  into  a single 
vessel,  the  capacity  of  it  would  be  much  less  than  that  of  a 
similar  vessel  made  by  the  union  of  all  the  veins.  This  dif- 
ference in  capacity  Avill  in  part  result  from  the  feebler  char- 
acter of  the  forces  which  propel  the  blood  through  the  veins 
than  through  the  arteries,  and  consequently  venous  obstruc- 
tion could  not  be  so  easily  overcome  as  if  it  were  in  the  ar- 
teries ; and  in  order  to  compensate  for  deficiency  in  power,  an 
increased  amount  of  tubing  is  provided. 

888.  Forces  of  the  Arterial  Circulation. — Theinquiry 
naturally  arises.  What  are  the  forces  that  send  the  blood 
through  the  circulatory  channels  ? 

389.  Contraction  of  the  Heart— Elasticit  y of  the  Mid- 
dle Coat. — In  the  first  place  the  contraction  of  the  heart  is 
the  most  essential  force  in  driving  the  blood  outwards.  This 
force  has  been  estimated  at  thirteen  pounds,  though  the  re- 

Why  do  the  arteries  near  the  heart  branch  off  at  a large  angle?  8S6.  Why  is  there  so 
large  an  amount  of  arteries  and  veins  ? 387.  What  is  the  comparative  capacity  of  tha 
veins  and  the  arteries  ? 358.  What  are  the  forces  of  the  circulation  ? 889.  What  is  said 
of  the  contraction  of  the  heart  ? What  is  the  estimate  of  the  force  that  it  exerts  2 

10* 


224 


HITCHCOCK’S  ANATOMY 


suit  can  not  be  relied  on  for  perfect  accuracy;  and  that  this  is 
no  inconsiderable  force  may  be  inferred  from  the  great  amount 
of  resistance  that  is  offered  to  this  current  from  the  ramifica- 
tions of  the  smaller  arteries,  whereby  the  velocity  is  increased 
as  well  as  the  surface  of  resistance.  It  may  also  be  seen  by 
wounding  an  artery  of  medium  size,  when  the  blood  is  sent 
out  in  jets,  and  sometimes  to  the  distance  of  several  feet. 
This,  however,  is  not  the  whole  amount  of  the  propulsive 
force  in  the  arterial  system,  for  the  middle  or  elastic  coat  as- 
sists by  a secondary  action.  When  the  ventricle  contracts,  or 
the  heart  beats,  the  blood  is  driven  into  the  aorta  and  its 
larger  branches  with  so  much  force,  that  the  middle  coat  yields 
considerably,  and  the  artery  is  distended  beyond  its  ordinary 
size.  As  soon  as  the  contraction  of  the  ventricle  ceases,  of 
course  the  blood  is  forced  back  towards  the  heart  by  the  elas- 
ticity of  the  artery.  But  as  soon  as  it  commences  to  flow  to- 
wards the  heart  the  semi-lunar  valves  close  at  once,  prevent- 
ing the  flow  in  that  direction,  so  that  the  whole  force  of  the 
artery  is  expended  in  driving  the  blood  towards  the  extremities. 

390.  Pressure  of  the  Muscles. — Another  power  which 
aids  in  the  propulsion  of  the  arterial  blood  is  the  pressure  of 
the  muscles  upon  the  arteries.  This  is  eflected  by  the  en- 
largement which  always  takes  place  in  the  belly  of  the  mus- 
cle whenever  it  is  used.  This  is  not  a constant  power,  acting 
only  during  exercise  of  the  muscles. 

391.  Forces  of  the  Venous  Circulation. — The  agencies 
by  which  the  blood  is  returned  to  the  heart  are  not  so  well 
known  as  those  just  considered.  The  valves  in  the  lining 
membrane  of  the  veins  seem  to  be  a contrivance  to  supply  the 
deficiency  of  power  to  drive  the  blood  back. 

392.  Pressure  of  the  Muscles. — The  jDressure  of  the 
muscles,  without  doubt,  is  another  important  impulse  in 

When  can  tlio  forces  of  tlio  circulation  in  arteries  be  well  seen?  ITow  does  the  mid- 
dle coat  as.sist  in  this  work?  Of  what  use  are  the  semi-lunar  valves?  890.  How  docs 
tlio  i)resfeure  of  the  muscles  aid  in  the  circulation?  891.  How  do  the  valves  aid  in  the 
vefious  circulation  ? 892.  Does  muscular  iiressurc  aid  in  this? 


AND  PHYSIOLOG’S. 


225 


aiding  the  return  of  blood  towards  the  heart.  For,  as  in  the 
aorta,  its  elasticity  forces  the  blood,  first  against  the  semi- 
lunar valves  and  then  onwards  through  the  arteries,  so  the 
muscles,  pressing  upon  the  veins,  urge  the  blood  into  the 
pouches  or  valves  on  their  inner  coat,  which,  preventing  re- 
gurgitation, assist  in  returning  it  towards  the  heart. 

393.  Respiration. — Respiration  is  another  cause  that 
greatly  aids  in  emptying  the  veins.  In  some  persons  a dis- 
tinct fullness  or  pulsation  of  one  of  the  veins  of  the  neck  is 
noticed  during  each  inspiration.  This  is  produced  by  the 
partial  vacuum  made  by  the  act  of  inhaling  air  ; that  is,  as  a 
pressure  is  produced  on  all  parts  of  the  body  by  the  atmos- 
phere, not  only  a rush  of  air  is  made  into  the  mouth,  but  the 
blood  is  forced  into  the  heart  by  the  same  cause.  And  could 
we  examine  all  the  large  veins  of  the  body  during  inspiration, 
without  doubt  we  should  see  the  blood  returning  rapidly  in 
them  at  each  inhalation  of  air. 

394.  Affinity  of  Venous  Blood  for  Oxygen.— The  afiSnity 
or  desire  of  venous  blood  for  the  oxygen,  and  the  arterial  for 
the  tissues,  are  important  causes  in  the  circulation,  and  es- 
pecially in  the  capillaries.  It  is  a principle  well  known  in 
physics,  that  if  two  fluids  of  diSerent  degrees  of  affinity  for  a 
third  fluid  meet  each  other  in  a capillary  tube,  the  fluid  hav- 
ing the  strongest  aflBnity  for  the  third  substance  will  either 
partially  or  wholly  force  out  the  other  fluid.  This  takes  place 
equally  well  through  porous  substances,  membranes,  or  capil- 
lary tubes. 

395.  So  that  when  pure  air  is  present  upon  one  side  of  the 
membrane  of  the  lungs  and  venous  blood  on  the  other,  the 
latter  urges  itself  onward  to  meet  the  oxygen,  and  thus  forces 
that  which  is  already  purifled  into  the  pulmonary  vessels,  and 
thence  into  the  heart. 

396.  The  same  thing  is  seen  in  the  capillaries  of  the  ex- 


393.  How  does  the  respiratory  act  aid  the  circulation  of  the  blood?  394.  How  does 
chemical  affinity  aid  in  the  circulation  ? 


226  HITCHCOCK’S  ANATOMY 

trcmities,  where  the  arterial  blood,  l)y  its  affinity  for  the 
healthy  tissues,  forces  along  that  Mhich  is  already  surcharged 
Avith  carbonic  acid  into  the  systemic  veins. 

397.  Forces  of  the  wliole  Circiilntioii. — The  forces,  then, 
which  propel  the  blood  through  the  whole  system  maybe  thus 
briefly  summed  up  : 

1.  Contraction  of  the  heart. 

2.  Elasticity  of  the  arteries. 

3.  Capillary  force. 

4.  Muscular  pressure. 

5.  Act  of  inspiration. 

6.  Arterialization  of  the  blood. 

398.  Course  of  the  lllood  lliroiigh  the  Body. — As  al- 
ready mentioned,  the  ventricles  are  the  propelling  and  the 
auricles  the  receiving  cavities.  Hence,  in  tracing  the  course 
of  the  blood  through  the  body,  beginning  Avith  the  left  ven- 
tricle, Ave  find  the  current  passing  through  the  aorta  and  ar- 
teries to  all  parts  of  the  body  except  the  lungs.  As  soon  as 
it  has  gone  through  the  capillaries  it  returns  to  the  right  au- 
ricle by  the  diflerent  veins,  from  which  cavity  it  passes  to  the 
right  ventricle,  and  thence  to  the  lungs.  After  it  has  received 
its  due  supply  of  oxygen,  it  is  received  by  the  left  auricle, 
from  which  it  passes  again  to  the  Avhole  system.  The  parts 
of  this  circle  and  their  order  are  as  follows  : left  ventricle,  ar- 
teries, capillaries,  veins,  right  auricle,  right  ventricle,  lungs, 
and  left  auricle.  Thus  we  see  that  the  whole  circulation  in 
man  and  all  mammalia  follows  through  the  body  a course 
represented  by  the  figure  8. 

399.  Relative  Time  Occupied  by  Contraction  of  Au- 
ricles and  Ventricles . — The  diastole  or  dilatation  of  auricles 
and  ventricles  occupies  a longer  period  of  time  than  the  cor- 
responding systole,  or  contraction.  If  we  divide  the  whole 


897.  Givo  a synopsis  of  tho  circulatory  forces.  89S.  Give  the  course  taken  by  the 
blood  as  it  circulates  through  tlie  body.  By  what  figure  may  it  be  represented?  899. 
What  is  tho  systole  and  diastole  of  the  heart  ? 


AND  PHYSIOLOGY. 


227 


/ 2 


Fig.  226. 

S ^ d G 


7 O 


portion  of  time  occupied  by  one  pulsation  into  eight  intervals, 
■vve  shall  find  that  the  auricles  employ  only  one  of  these  in- 
tervals in  contraction,  and  the  remaining  seven  by  dilatation ; 
while  the  time  occupied  by  the 
contration  of  the  ventricles  is 
the  same  as  their  dilatation,  as 
may  be  seen  in  the  diagram. 

400.  The  Sounds  of  the 
Heart — Cause  of  the  First 
and  Second  Sound —If  the 
ear  be  applied  over  the  heart 
of  a healthy  person,  two 
sounds  will  be  heard,  one 
of  which  corresponds  in  time 
with  the  pulsation  noticed 

. Diagram  showing  the  relative  Time  occu- 

at  the  wrist,  or  any  other  pied  by  the  Contraction  of  the  Auricles  and 

large  artery  of  the  body.  Ventncles,  the  converging  imes  from  ^ 
o •'  ^ right  indicating  the  contraction,  and  the  di- 

These  sounds  do  not  corre-  verging  ones  the  dilatation. 


Auricles. 


Yentricles. 


spond  to  each  other  in  intensity  or  duration,  but  are  some- 
what indefinitely  represented  by  the  sounds  given  to  the  mono- 
syllables ^Mub’’  and  '^dup;’’  the  first  a long  and  heavy 
sound,  and  the  second  a short  and  light  one.  The  first  sound 
is  undoubtedly  caused  by  the  contraction  of  the  heart,  the 
rush  of  blood,  and  the  impulse  of  the  organ  against  the  side 
of  the  chest ; while  the  second  is  the  clicking  of  the  semi- 
lunar valves  as  they  close  at  the  commencement  of  the  aorta 
after  the  ventricular  contraction.  That  the  last  sound  is  due 
to  this  cause  is  proved  by  an  experiment  performed  on  a dog, 
of  introducing  a hook  through  the  aorta,  and  holding  back  one 
of  these  valves,  when  the  second  sound  entirely  failed. 

401.  Number  of  Pulsations  per  Minute. — The  number 
of  pulsations  of  the  heart  varies  considerably  at  different  pe- 
riods of  life.  Thus  the  following  table  shows  the  average 
number  of  pulsations  each  minute  at  different  ages  : 


Give  the  relative  time  occupied  by  the  contraction  and  dilatation  of  the  auricles  and 
ventricles.  400.  What  two  sounds  are  made  at  each  complete  pulsation  of  the  heart? 
Give  the  causes  of  the  first  sound.  What  is  the  last  sound  owing  to  ? What  proof  of 
it? 


228 


11  ITCH  COCK’S  ANATOMY 


New-born  infiint. 130  to  140 

During  the  1st  year 115  “ 130 

“ “ 2d  “ 100  “ 115 

From  the  7th  to  the  14th  year 80  “ 90 

“ 14th  “ 21st  “ 75  “ 85 

“ 21st  “ GOth  70  “ 75 

Old  ago 75  “ 80 


402.  Causes  affecting  the  Pulsations. — Muscular  exer- 
tion lias  a considerable  influence  upon  the  rapidity  of  the  con- 
traction of  the  heart.  So  also  has  the  position  of  the  body, 
whether  sitting,  lying,  or  standing.  The  time  of  day  or 
night  likewise  has  an  important  influence,  the  highest  number 
of  pulsations  being  found  at  noon,  and  the  fewest  at  mid- 
night. 

403.  Use  of  the  Corpuscles. — The  function  of  the  Red 
Corpuscles  seems  to  be  to  convey  oxygen  to  the  tissues,  and 
as  this  is  the  agent  which  is  continually  promoting  the  change 
or  waste  of  the  system,  these  corpuscles  seem  to  be  the  great 
agents  for  disassimilating  the  tissues  and  the  blood  itself.  The 
colorless  or  white  corpuscles  seem  to  be  the  agents  by  which 
the  repair  of  the  body  is  effected,  since  they  are  greatly  aug- 
mented in  number  when  there  is  a large  wound  to  be  healed, 
or  when  there  is  a great  amount  of  internal  or  external  in- 
flammation. 

403a.  Statistics. — In  an  ordinary  life  of  a man  the  heart 
beats  at  least  3, 000,001), 000  times,  and  propels  through  the 
aorta  one  half  a million  tons  of  blood. 


HYGIENIC  INFERENCES. 

404.  hut  few  Diseases  of  the  Circulatory  Organs. — 
1.  Though  the  blood-vessels  are  so  constantly  in  use,  and  so 
easily  excited  by  every  muscular  movement  and  mental  emo- 
tion, yet  they  are  affected  by  only  a few  diseases,  and  many 


401.  State  the  miinher  of  pulsations  of  the  heart  at  different  periods  of  life.  402.  What 
causes  modify  the  number  of  the  pulsations?  403.  What  is  the  probable  business  of  the 
lie(l  Corpubclcb?  What  of  the  White?  404.  Arc  there  many  diseases  of  the  Circulatory 
organs  ? 


AND  PHYSIOLOGY. 


229 


of  these  aifectionSj  which  seem  to  be  diseases  of  the  heart,  are 
merely  sympathetic,  and  the  difficulty  lies  in  other  organs. 

405.  Avoidance  of  sudden  Efforts. — 2.  But  those  per- 
sons who  have  a tendency  to  diseases  of  the  heart,  sympa- 
thetic or  organic,  should  be  on  their  guard  against  sudden 
exertions,  and,  to  as  great  an  extent  as  possible,  avoid  mental 
anxiety  and  alarms.  Heart  diseases  are  most  common  late  in 
life,  at  or  about  sixty  years  of  age. 

406.  Principal  Danger  from  Wounds.— Treatment  of 
IVounds  of  Arteries. — 3.  The  principal  danger  to  be  feared 
from  these  organs  results  from  wounds.  If  these  are  in  the 
arteries,  they  require  prompt  attention,  but  if  in  the  veins, 
they  need  scarcely  ever  excite  fear.  If  an  artery  be  wounded 
— which  can  always  be  known  by  the  escape  of  blood  in  jets, 
and  not  a steady  stream — the  wound  should  be  either  closed, 
or  the  artery  pressed  upon  between  the  wound  and  the  heart 
with  so  much  force  as  to  stop  the  flow  of  blood  through  it. 
In  case  of  any  such  arterial  wound  it  will  always  be  well  to 
tie  a bandage  as  tight  as  possible  immediately  over  the  wound, 
and  then  compress  the  artery  as  already  mentioned.  If  the 
wound  be  on  the  hand  or  forearm,  the  brachial  artery  may  be 
found  and  compressed  just  above  the  inner  angle  of  the  elbow. 
Or  if  it  is  desirable  to  compress  the  artery  still  higher  up,  the 
axillary  artery  may  be  found  in  the  armpit,  where  by  pressing 
outwards,  nearly  all  the  blood  flowing  to  the  arm  may  be 
checked. 

407.  Method  of  Checking  the  Blood  to  the  lower  Ex- 
tremities .—4.  If  it  is  desired  to  check  the  flow  of  blood  to  the 
lower  extremity,  the  popliteal  artery  lies  directly  against  the 
femur  upon  the  backside  of  the  knee-joint,  where  a compres- 
sion of  it  may  be  effected  with  great  advantage.  Nearer  the 
heart  (in  the  groin)  the  femoral  artery  is  found,  where  it 

405.  What  should  those  persons  j)re{Iisposed  to  these  diseases  especially  be  on  their 
guard  against?  At  what  time  of  life  are  Heart  diseases  the  most  frequent?  408.  How 
can  we  distinguish  between  the  wound  of  a vein  and  that  of  an  artery  ? How  may  ar- 
terial hemorrhage  be  most  readily  checked  in  the  upper  extremities  ? 407.  How  may  it 
be  checked  in  the  lower  extremities  ? 


230 


niTC  II  cock’s  anatomy 


crosses  the  os  innominatum  lying  just  beneath  the  skin.  Hero 
an  eflScient  compression  may  be  made,  since  all  the  anterior 
part  of  the  thigh  and  the  whole  of  the  leg  proper,  is  supplied 
with  blood  from  this  artery. 

408.  5.  Except  bad  wounds,  however,  a tightly  drawn  band- 
age, directly  over  the  wound,  thoroughly  wet  with  cold  water, 
will  check  hemorrhage  suflSciently,  until  a surgeon  can  be 
called. 


COMPARATIVE  ANGIOLOGY. 


409.  Heart  of  Manimals.- 


Fig.  22Y. 


Circulation  in  Man.  a.  Eight  Auricle. 
h.  liiglit  Ventricle,  e.  Left  Auricle,  d. 
J.eft  Ventricle,  e.  Aorta,  f.  Vena  Cava. 
(j.  Pulmonary  Artery.  h.  Pulmonary 
Veins. 


In  all  mammals  the  heart  is 
divided  into  four  cavities,  as 
in  man.  Its  form,  however,  is 
more  rounded  and  less  elon- 
gated. In  one  species  of  the 
whale  this  organ  is  cleft  in  a 
peculiar  manner,  the  division 
between  the  two  ventricles 
being  indicated  externally  by 
a deep  fissure  in  its  apex.  In 
the  Ox,  Hog,  Sheep,  and 
Goat  there  are  always  found 
one  or  two  bones  in  the  di- 
visions between  the  ventri- 
cles. In  most  mammals  it 
is  placed  more  in  a right  line 
with  the  middle  of  the  body, 
and  not  so  obliquely  as  iu 
man. 


403.  What  treatment  will  chock  all  ordinary  hemorrhages?  409.  What  is  peculiar  m 
the  heart  of  the  Whale,  the  O.v,  the  Sheep,  and  Goat?  Where  is  the  heart  located  ic 
quadrupeds  ? 


AND  PHYSIOLOGY. 


231 


410.  Aorta  and  Pulmonary  Veins.— The  manner  in  which 
the  Aorta  and  its  branches  are  given  off  varies  greatly  in  these 
animals,  as  may  be  seen  by  the  cut.  The  number  of  Pulmo- 

Fig.  228. 


A BODE  FGH 


a ha  ha  h a h a ha  hah  a 


Diagram  of  the  Principal  Varieties  of  the  Aorta  in  its  Principal  Branches  in  a,  Man  ; 
B,  Elephant  c,  Cetacea;  d,  Bat;  e,  Carnivora;  r.  Seal;  G»  Euminants  ; n,  Reptiles. 
1,  Eight  Subclavian.  2,  Eight  Carotid.  3,  Left  Carotid.  4,  Left  Subclavian.  5,  Verte- 
bral. a,  Ascending  and  b Descending  Aorta. 


nary  Veins  varies  upon  the  different  sides  of  the  body,  and 
is  generally  according  to  the  number  of  lobes  in  the  lungs, 
the  relations  of  the  sides  being  represented  by  the  formula 
3f2. 


411.  Economy  of  Diving  Animals. — In  diving  animals  the 

vena  cava  is  capable  of  great  dilatation,  in  order  to  contain  an 
unusual  quantity  of  blood  which  accumulates  there  when  the 
animal  suspends  respiration  under  water,  since  it  can  not  be 
purified  except  in  the  lungs.  Still  further  protection  to  the 
heart  in  diving  animals  is  seen  in  the  vena  cava  ascendens, 
where  a circular  muscle,  by  its  contraction,  can  completely  cut 
off  the  flow  of  blood  to  the  heart  Fig.  229. 

from  the  lower  extremities. 

412.  Blood  Corpuscles  of 
Mammals — Wonder  Nets. — 

The  blood  of  mammals,  for 
the  most  part,  presents  small 
round,  disc-shaped  corpuscles, 
similar  to,  but  smaller  than  those  in  man.  This  is  especially 


B A 

Eed  Corpuscles  of  the  Ox.  A,  In  their 
Natural  State,  a,  Seen  in  Profile.  Seen 
on  the  Surface.  B,  Altered  Corpuscles. 


410.  What  is  peculiar  about  the  aorta  and  pulmonary  veins  in  many  mammals?  411, 
What  is  the  arrangement  of  the  vena  in  diving  animals  ? 


232 


n ITCH  cock’s  anatomy 


-r^K  - •; 


true  of  ruminants.  The  largest  animals,  such  as  the  elephant, 
have  very  small  corpuscles.  In  some  of  the  camels  and  llamas 
the  corpuscles  are  large  and  somewhat  elongated.  The  same 
Fig.  230.  is  true  of  the  dromedary. 

Crystalline  substances 
are  found  in  the  blood 
of  other  mammals  as 
well  as  man.  The  an- 
nexed cut  shows  crystals 
from  the  blood  of  the 
Guinea  pig. 

The  distribution  ot 
the  arteries  of  quadru- 
peds is  a subject  of  con- 
siderable interest.  In 
grazing  animals,  which 
Blood  Crystals  of  the  Guinea  Pig.  hold  their  heads  low,  in 

addition  to  large  arterial  trunks,  we  find  a great  number  of 
very  small  ones,  which  are  exceedingly  tortuous  in  their  course, 
called  Wonder  Nets.”  This  arrangement  is  to  prevent  a too 
rapid  flow  of  blood  to  the  head  by  the  force  of  gravity,  which 
■would  of  necessity  take  place  when  the  head  is  so  constantly 
in  a dependent  position.  A similar  disposition  is  seen  in  the 
limbs  of  the  sloth  and  other  animals  which  are  like  them  in 
tardiness  of  movement.  In  the  fore-leg  of  the  lion,  where 
great  muscular  force  is  exerted,  the  main  artery  passes  through 
a perforation  in  the  bone,  so  as  to  secure  it  from  obstruction 
to  the  flow  of  blood  by  pressure  of  the  rigid  muscles. 

413.  Heart  of  Birds. — The  heart  of  birds  is  highly  mus- 
cular and  of  very  large  size  in  proportion  to  the  bulk  of  the 
body,  and  in  general  structure  resembles  the  same  organ  in 
mammals.  The  valves  of  the  right  ventricles,  how^ever,  are 
supplied  with  a strong  band  of  muscular  fibers,  which  gives 


-112.  Whiit  is  i>eculiar  about  tlio  blooil  discs  or  cori»nscle.s  of  the  larger  animals? 
What  is  the  form  of  nearly  all  of  them?  In  Avluit  animals  ar  c they  oval  ? What  are 
Winder  Nets,  and  why  arc  they  introduced?  413.  What  is  worthy  of  note  with  refer- 
ence to  the  heart  of  birds  ? 


AND  PHYSIOLOGY 


233 


Why  ao  the  valves  have  au  especial  muscle? 


additional  impulse  to  the  blood  as  it  is  forced  into  the  pulmo- 
nary arteries  The  need  of  this  arrangement  is  to  give  a full 
supply  of  blood  to  the  lungs,  which  the  ordinary  powers  of 
the  heart  could  not  effect. 

Fia.  231. 


Arterial  System  of  a Bird. 

Arteries  of  the  Grebe,  a,  Aorta,  aw,  One  of  its  large  Branches.  It  gives  off  the 
Carotid  (ac)  and  Subclavian,  is  ultimately  distributed  to  the  muscles  of  the  chest,  and 
corresponds  to  the  mammary  arteries  of  mammals,  a-y,  One  of  the  Branches  of  the 
Vertebral  Artery  supplying  the  Muscles  of  the  Shoulder,  ce.  Arterial  Loops  formed  by 
the  Branches  of  the  External  Carotid,  al.  Lingual  Artery,  t,  Trachea,  or  wind-pipe, 
ar.  Renal  Arterie.s.  at,  Ischiatic  Artery  proceeding  to  the  lower  extremities,  as.  Sac- 
ral Artery,  forming  a continuation  of  the  Aorta,  and  giving  origin  to  the  Inferior  Mesen- 
teric Artery,  etc.  cl,  The  Cloaca. 


234 


HITCHCOCK’S  ANATO]SIY 


414.  Arteries — Wonder  Jlets. — The  trunk  of  tlic  aorta  is 
very  short,  and  after  giving  arteries  to  supply  the  heart  it  di- 
vides at  once  into  two  large  branches,  quite  unlike  the  con- 
formation in  mammalia.  Wonder  nets,  too,  are  often  found 
in  birds,  and  especially  in  those  arteries  supplying  the  brain, 
eyes  and  legs. 


415.  Blood. — The  blood  of 


Fig.  232. 


birds  has  the  highest  tem- 


0 perature  of  the  vertebrate 


animals — 110°  F.  The  blood 


cells,  or  corpuscles,  are  al- 
ways of  an  elliptical  form  and 
of  a very  uniform  diameter. 


A 


Pigeon’s  Blood  (red)  Corpuscles  Magni- 
fied 4U0  Diameters.  A,  In  Natural  State. 
B,  Altered  by  Acetic  Acid. 


416.  Heart  of  Reptiles. — 


The  heart  of  reptiles  ordinarily  consists  of  a single  ventricle, 


Fig.  233. 


Fig.  234. 


or  propelling  cavity,  and  two  auri- 
cles, or  receiving  cavities,  so  that 
the  pure  blood  is  mixed  with  the 
impure  (or  a portion  of  it)  as  it 


Circulation  In  Reptiles,  a,  Heart, 
b.  Ventricle,  c,  c,  Auricles. 


comes  from  the  lungs,  which  accounts  in  part  for  the  general 
sluggishness  of  these  animals.  The  blood  corpuscles  of  rep- 
tiles are  large  and  oval,  as  may  be  seen  in  Fig.  234. 

'll 4.  Into  how  many  branches  does  the  aorta  at  once  divide  ? Where  are  wonder  nets 
found  in  binls?  415.  Wliat  is  said  of  the  temperature  of  birds  ? What  of  blood-cells  ? 
416.  Describe  the  heart  of  reptiles.  What  is  the  elfoct  upon  the  blood?  What  is  the 
size  of  their  blood-vessels? 


AND  PHYSIOLO  GY. 


235 


417.  Blood-Vessels. — The  arrangement  of  Blood-Vessels 
is  very  diverse,  since  one  portion  of  them  breathe  by  gills  and 
another  by  lungs,  while  frogs  in  their  early  condition  are  fur- 

Fia.  235. 


Carotid 

/Artery. 


Arches  of  ^ 
the  Aorta.  N 


Right 

Auricle. 


Intestines. 


Circulatory  Apparatus  in  the  Lizard. 


417.  Why  are  blood-vessels  arranged  differently  in  many  of  the  reptiles  ? 


236  HITCHCOCK’S  anatomy 

nislied  Avitli  the  former,  but  in  adult  age,  after  passing  tlirougli 
a metamorphosis,  have  the  latter  system  of  respiratory  vessels. 

418.  Heart  of  Crocodile. 
— Crocodiles  and  turtles  ex- 
hibit the  most  perfect  form  of 
heart,  for  it  agrees  essentially 
with  that  of  mammals,  as  may 
be  seen  in  Figs  236  and  237. 
But  there  is  a small  opening 
just  at  the  outlet  of  the  two 
ventricles,  so  that  the  pure 
and  impure  blood  is  mixed. 

419.  Portal  System.— 
Reptiles  have  a double  Portal 
System,  one  set  of  vessels 

supplying  the  kidneys  and  another  the  liver. 

420.  Lymphatic  Hearts. — Many  reptiles  have  small  sac- 
like  organs  lying  just  beneath  the  skin  in  certain  portions  of 
the  body,  wdiich,  from  their  containing  lymph  and  showing 

Fig.  231. 


pulsations,  are  called  Lymphatic  Hearts.  In  the  Frog,  two 
such  hearts  are  situated  on  the  back  of  the  animal,  between 
the  joints  of  the  thigh  bones. 


Fig.  236. 


ao  c c a 


Heart  of  Crocodile.  Veins,  rto,  Uijjht 
Auricle,  'vt.  Ventricles,  ap,  Pulmonary 
Arteries,  or,  A Vessel  proceeding  from  the 
Ventricle  to  the  Aorta,  og,  Left  Auricle. 


4 IS.  What  animals  of  this  class  have  the  most  pc'rfcct  form  of  a heart?  419.  What  kind 
of  a iK)rtttl  system  do  wo  liiul  among  reptiles?  420.  Describe  lymphatic  hearts. 


AND  PHYSIOLOGY. 


237 


421.  Heart  of  Fishes. — The  heart  consists  of  one  auricle 
and  one  ventricle,  which  are  covered  bj  a pericardium,  and 
the  whole  organ  is  very  small  in  proportion  to  the  size  of  the 
whole  body,  being  from  4 ^ 


to  T oV  weight.  In  the 

osseous  fishes  the  heart  is 
elongated  and  conical,  while 
in  the  Sharks  and  Rays  it  is 
broader.  The  ventricle  dis- 
charges its  blood  through  the 
aortic  trunk  upon  the  gills. 
This  trunk  divides  up  into 
a large  number  of  minute 
branches  w^hich  ramify  upon 
the  gills,  and  after  the  blood 
has  received  its  oxygen  from 
the  water,  it  is  collected  by 
a corresponding  set  of  ves- 
sels, and  emptied  into  another 
trunk  which  supplies  all  the 
rest  of  the  body — which  trunk 
corresponds  to  the  aorta — 
though  it  has  no  muscular 


Fig.  238. 

dj 


Circulation  in  Fishes.  «,  Heart, 
Auricle,  c,  Ventricle.  Circulation 

through  the  Gills,  or  Lesser  Circulation. 
(7,  Circulaticn  through  the  Body,  or 
Greater  Circulation,  e,  Arteries.  ^ Veins. 


power  to  propel  the  blood  along.  After  it  has  performed  its 
office  it  is  collected  by  a system  of  vessels  similar  to  veins, 
and  returned  to  the  auricle. 


422.  Pulsations  in  a Minute. — Commonly  not  more  than 
twenty  or  thirty  beats  in  a minute  may  be  counted  in  fishes, 
while  in  birds  one  hundred  may  be  counted  in  the  same 
time. 

423.  Portal  Circulation. — In  fishes,  as  in  reptiles,  there 
seems  to  be  a double  portal  circulation. 


421.  Why  is  the  heart  of  the  osseous  fishes  called  abranchial  heart?  What  proportion 
of  the  body  docs  it  constitute  ? Give  tlie  course  of  circulation.  422.  What  number  of 
pulsations  can  bo  counted  in  the  heart  of  fishes,  and  what  number  in  birds  ? 


238 


HITCHCOCK’S  ANATOMY 


FlO.  239. 


424.  Accessory  Hearts-— Caudal  Heart. — Among  many 
fishes  are  found  what  are  termed  Accessory  Hearts,  or  small 
muscular  organs  which  seem  to  aid  in  the  propulsion  of  blood 
through  the  difierent  parts  of  the  body.  Thus,  in  the  myxine, 
the  portal  vein  is  distended  into  a large  sac,  which  expands 
and  contracts  alternately;  and  in  eels  there  is  found  upon 


424.  Wbat  are  the  accessory  hearts  of  fishes  7 


AND  PHYSIOLOGY. 


239 


both  sides  of  the  last  caudal  vertebra  a pulsating  organ  which 
receives  the  blood  from  the  delicate  veins  of  the  caudal  fin, 
and  propels  it  into  the  caudal  vein,  this  constituting  a true 
caudal  heart. 

425.  Fishes’  Blood. — The  blood  of 
fishes,  almost  without  exception,  is  of  a 
red  color,  and  contains  oval  and  slightly 
bi-convex  corpuscles.  In  one  family 
they  are  distinguished  by  their  great 
size,  and  thus  resemble  those  of  frogs ; 
but  other  families  have  smaller  ones. 

Fig.  241. 

Smaller  Circulation. 

Branchio-Cardia« 

Canals. 


Heart. 


Arteries. 


Greater  Circulation. 

Diagram  of  the  Circulation  in  Fishes. 

426.  Dorsal  Vessel,  or  Heart  of  Articulates. — In  ar- 
ticulata,  a vessel  or  tube  passes  along  the  back  of  the  body — 
behind  the  intestines  and  in  front  of  the  chain  of  ganglia — 
called  the  Dorsal  Vessel,  which  is  divided  into  as  many  por- 
tions as  there  are  segments  of  the  body.  This  is  really  tha 


Fig.  240. 


Blood  Corpuscles  of  a, 
Lamprey  Eel ; Skate. 


What  peculiarity  in  the  tail  of  the  eel  ? 4-5.  What  is  the  color  of  fishes’  blood,  and 
what  are  its  corpsucles  ? 426.  WTiat  is  the  Dorsal  Vessel  of  articulates  ? 

11 


240 


HITCHCOCK’S  ANATOMY 


Fia.  242. 

e fia  d J)  a 


Circulatory  Apparatus  in  the  Lobster.  <x,  The  Heart,  b,  Ophthalmic  Artery,  c,  An- 
tennar  Artery,  c?,  Hepatic  Artery,  e,  Abdominal  Artery.  /,  Sternal  Artery,  c',  Venous 
Sinuses,  h,  Branchia?. 

heart  of  the  animal,  since  by  the  contraction  of  its  coats  the 
blood  or  contained  fluid  is  forced  along.  Small  arteries  are 
given  oS*  from  this  dorsal  vessel  all  along  its  course.  This 


Fig.  243. 


Circulation  in  Insects,  a,  Dorsal  Vessel,  b,  Principal  Lateral  Currents.  The  Arrow! 
show  the  direction  of  the  Fluid. 


plan,  however,  is  seldom  completely  carried  out,  but  is  most 
fully  exemydified  in  the  class  of  insects  which  is  partly  ex- 
hibited in  Fig.  248. 


AND  PHYSIOLOGY. 


241 


427.  Ventral  Trunk . — The  blood  which  is  driven  forwards 
by  this  dorsal  vessel  is  collected  by  a set  of  vessels  which  unite 
into  a large  tube  called  the  Ventral  vessel,  or  trunk,  which 
returns  it  to  the  posterior  part  of  the  body. 


428.  Blood  of  Articulates. — This  fluid  called  blood  is  a 
thin  liquid,  yellowish  brown,  red,  green,  or  even  colorless, 
and  never  containing  corpuscles ; and  the  only  reason  why  it 
is  called  blood  is,  that  it  circulates  like  the  blood  of  the 
higher  animals. 


429.  Cliylaqucous  Fluid. — But  besides  this  fluid  there  is 
another  found  in  the  general  or  abdominal  cavity  of  the  body, 
which,  though  not  contained  in  organs  expressly  designed  for 
its  circulation,  yet  is  rapidly  carried  through  the  body  by 
means  of  the  motion  of  the  different  segments  of  the  animal, 
which  in  many  of  this  order  is  incessant.  This  fluid,  unlike 
the  true  blood,  is  rich  in  corpuscles  and  easily  coagulated, 
which  gives  it  one  of  the  essential  characteristics  of  true  blood 
in  the  higher  animals.  It,  however,  must  probably  be  re- 
garded as  the  cylaqueous  fluid  of  many  of  the  lower  verte- 
brata.  Scorpions  have  arteries  and  veins. 


430.  Heart  and  Blood  Fig.  244. 

of  Crustacea. — Amongthe 
crustaceans,  such  as  the  crab 
and  lobster,  we  find  a vessel 
much  shorter  than  the  dorsal 
vessel  of  most  articulata, 
which  resembles  a heart  from 
the  fact  that  it  is  a propel- 
ling organ  and  has  muscular  fibers  in  its  coats.  The  blood  in 
these  animals  is  of  a whitish  or  purple  color,  and  the  pulsa- 
tions of  the  heart  vary  in  number  from  fifty-one  to  two  hun- 
dred per  minute. 


Blood  Corpuscles  of  the  Crab. 
Cells.  B,  Nucleated  Colls. 


427.  TTow  is  the  blood  returned  that  is  circulated  by  the  dorsal  heart?  428.  Describe 
the  blood  oT  articulates.  429.  What  other  Iluid  is  found  in  these  animals  ? 430.  What  is 
said  of  the  heart  and  blood  of  the  crab  and  lobster  ? 


242 


HITCHCOCK’S  ANATOMY 


431.  Circulation  in  Molluscs. — The  higher  orders  of 
molluscs  show  a system  of  circulating  vessels  which  seem  to 
be  arteries  and  veins,  with  a central  vessel  answering  to  a 
heart.  There  is  usually  a ventricle  corresponding  to  the 
right  ventricle  in  man,  to  send  the  blood  to  the  respiratory 
organ.  There  is  also  another  cavity  which  corresponds  some- 

Fig.  245. 


Anatomy  of  the  Snail,  cr,  Mouth.  5,  Foot.  <7,  Lung,  e.  Stomach.  / Intestine,  gr, 
Liver,  h,  Heart,  Aorta.  / Gastric  Artery.  7,  Hepatic  Artery,  k,  Artery  of  the 
Foot.  971,  Abdominal  Cavity,  'll,  Canal  conveying  the  Blood  to  the  Lungs,  o,  Vessel 
carrying  Blood  from  Lung  to  Heart. 

what  to  an  auricle,  which  receives  the  blood  as  it  enters  the 
heart.  But  with  the  exception  of  the  vessels  carrying  blood 
to  the  gills,  there  are  few  separate  tubes  for  carrying  this 
fluid  through  the  body,  it  being  left  to  circulate  by  imbi- 
bition, or  it  is  efiected  by  means  of  the  lacunar  spaces,  Fig. 
245. 

432.  Blood  of  Molluscs. — The  blood  of  these  animals  is 
generally  destitute  of  corpuscles,  and  is  sometimes  colorless, 
though  often  white,  brown,  red,  or  green. 

433.  Contractions  of  the  Heart. — The  heart  does  not 


481.  What  are  the  circulatory  vessels  in  molluscs?  How  is  most  of  the  fluid  circu- 
lated? 432.  What  of  the  blood  of  molluscs? 


AND  PHYSIOLOGY. 


243 


expand  and  contract  regularly,  but  in  a spiral,  screw-like 
manner,  like  the  peristaltic  motion  of  the  intestines. 

434.  Circulation  in  the  Radiata  and  Protozoa. — In  a 
few  polyps  a vascular  system  is  quite  obvious,  and  may  be 
inferred  in  them  all.  The  blood  is  colorless,  and  has  white 
corpuscles.  In  the  Acalephac  there  exists  a circulating  fluid, 
which  is  thought  by  Agassiz  and  Dana  to  be  merely  water, 
intended  to  subserve  the  purposes  of  respiration  rather  than 
nutrition.  The  Echinoderms  have  one  heart,  and  sometimes 
more.  The  Infusoria  have  pulsatory  cavities,  but  no  system 
of  circulation. 


433.  How  does  the  heart  pulsate  ? 434.  What  is  the  plan  of  circulation  among  the 
radiate  animals  ? 


CHAPTER  FIFTH. 


PNEUMONOLOGT,  OR  HISTORY  OF  THE  ORGANS  OF  BREATHING. 
—THE  RESPIRATORY,  VOCAL,  AND  CALORIFIC  ORGANS. 


DEFINITIONS  AND  DESCRIPTIONS. 

435.  location  of  Respiratory  Organs— Sympathy  be- 
tween the  Heart  and  lungs. — Within  the  thorax  are  con- 
tained not  only  the  central  organs  of  circulation,  but  other 
organs  closely  related,  and  connected  with  them,  the  Hespira- 

Fm.  246. 


x)  t rj 


od  xc  xd  a xg 


Lungs,  Heart,  and  Principal  Vessels  in  Man.  od.  Right  Auricle,  xd.  Eight 
Ventricle,  xg.  Left  Ventricle,  a.  Aorta,  ac..  Carotid  Arteries,  xc.  Vena  Cava. 
t.  Tracliea.  -wj,  Jugular  Veins. 

435.  What  organs  are  contained  in  the  thorax?  What  is  said  of  the  sympathy  he- 
tween  the  respiratory  and  clrciilatury  organs? 


ANATOMY  AND  PHYSIOLOGY. 


245 


tory.  These  are  not  only  related  by  position,  but  are  mutu- 
ally dependent  on  each  other  for  their  action.  Thus,  if  severe 
disease  affect  the  heart,  the  lungs  are  very  apt  by  imperfectly 
or  irregularly  performing  their  offices,  to  show  their  sym- 
pathy. In  like  manner,  if  the  lungs  exhibit  disease, 
sooner  or  later  the  heart  is  sure  to  manifest  its  sympathy 
with  its  suffering  neighbors. 

486.  The  Lungs,  their  Shape,  their  Color,  Lobes  of 
the  Right  lung,  Capacity  of  the  Right  Lung,  Amount  of 

FiO.  247. 


A View  of  the  Bronchia  and  Blood-Vessels  of  the  Lungs  as  shown  by  Dissection, 
as  well  as  the  relative  Position  of  the  Lungs  to  the  Heart.  1,  End  of  the  Left  Au- 
ricle of  the  Heart.  2,  The  Bight  Auricle.  3,  The  Left  Ventricle  with  its  Vessels. 
4,  The  Bight  Ventricle  with  its  Vessejs.  5,  The  Pulmonary  Artery.  G,  Arch  of  the 
Aorta.  7,  Superior  Vena  Cava.  8,  Artcria  Innominata,  9,  Left  Primitive  Carotid 
Artery.  10,  Left  Sub-Clavian  Artery.  11,  The  Trachea.  12,  The  Larynx.  13,  Lp 
per  Lobe  of  the  Bight  Lung.  14,  Upper  Lobe  of  the  Left  Lung.  15,  Trunk  of  the 
Bight  Pulmonary  Artery.  16,  Lower  Lobes  of  the  Lungs.  I'he  Distribution  of  the 
Bronchia  and  of  the  Arteries  and  Veins,  as  well  as  some  of  the  Air-Cells  of  the  Lungs, 
arc  also  shown  in  this  dissection. 


246 


HITCHCOCK’S  ANATOMY 


Blood  in  cncli  lung. — The  essential  organs  of  respiration 
are  the  Lungs.  These  are  light  solids,  two  in  number,  and 
occupy  nearly  four  fifths  of  the  cavity  of  the  chest.  They 


Fig.  248. 


An  Anterior  View  of  the  Thoracic  Viscera  in  Situ,  as  shown  by  the  Eemoval  of  their 
Anterior  Parietes.  1,  Superior  Lobe  of  the  Ei^ht  Lung.  2,  Its  Middle  Lobe.  3,  Its 
Inferior  Lobe.  4,  4,  Lobular  Fissures.  5,  5,  Internal  Layer  of  the  Costal  Pleura  form- 
ing the  Eight  Side  of  the  Anterior  Mediastinum.  6,  6,  The  Eight  Diaphragmatic  Por- 
tion of  the  Pleura  Costalis.  7,  7,  The  Eight  Pleura  Costalis  on  the  Eibs.  8,  Superior 
Lobe  on  the  Left  Lung.  9,  Its  Inferior  Lobe.  10,  10,  Interlobular  Fissures.  11,  The 
Portion  of  the  Pleura  Costalis  Avhich  forms  the  Loft  Side  of  the  Anterior  Mediastinum. 
12,  The  Left  Diaphragmatic  Portion  of  the  Pleura  Costalis.  13,  Left  Pleura  Costalis. 
11,14,  The  Middle  Space  between  the  Pleurae,  known  as  the  Anterior  Mediastinum. 
15,  The  Pericardium.  10,  Fibrous  Partition  over  which  the  Pleurae  are  reflected.  17 
The  Tr.achea.  18,  Thyroid  Claud.  19,  Anterior  Portion  of  the  Thyroid  Cartilage.  20^ 
Primitive  Carotid  Artery.  21,  Subclavian  Vein.  22,  Internal  Jugular  Vein.  23,  Bra- 
chio-Cephalio  Vein.  24,  Abdominal  Aorta.  25,  Xiphoid  Cartilage. 


430.  What  are  the  Lungs? 


AND  PHYSIOLOGY. 


247 


are  of  a conical  shape,  the  apex  pointing  upwards,  the  base 
resting  on  the  Diaphragm,  of  a pinkish  gray  color,  frequently 
dotted  with  black  spots,  and  divided  by  a deep  fissure  into 
two  lobes.  The  right  lung  is  shorter  in  its  long  diameter 
than  the  left,  on  account  of  the  liver  which  raises  the  right 
side  of  the  diaphragm  higher  than  the  left.  The  right  lung 
is  subdivided  again,  so  that  it  is  really  made  up  of  three  lobes 
instead  of  two.  It  has  also  a larger  capacity  than  the  left, 
since  the  position  of  the  heart,  considerably  upon  the  left 
side  of  the  median  line  of  the  body,  occupies  a portion  of  the 
left  thorax.  Each  of  the  lungs  ordinarily  contains  a pint  of 
blood. 

437.  Lobules  of  the  Lungs. — A closer  examination  of  the 
lungs  shows  them  to  be  made  up  of  small  bodies  called  Lung- 
lets.  These  are  from  4^3  th  to  j\ih.  of  an  inch  in  diameter,  and 
of  a conical  or  pyramidal  shape.  They  are  much  more  clearly 
defined  in  small  children  than  in  adults.  Fig.  249,  by  the 

Fig.  249. 


A Lunarlet  with  a Section  of  a Bronchial  Tube.  «,  Bronchus,  b and  c,  Vessels  of 
Bronchial  Lining  Membrane.  c?,  e,  Spaces  between  contiguous  Lobules,  contain- 
ing Ihe  Terminal  Pulmonary  Arteries  and  Veins  supplying  the  Capillary  Plexus  {/,  /^) 
to  the  Meshes  of  which  the  air  gains  access  by  the  Lobular  Passages. 


Give  their  shape,  color  and  division.  What  are  the  lobes  of  the  lungs?  Which  is  the 
largest  lung,  and  why  the  diiference  ? 437.  How  are  the  lungs  made  up?  At  what  pe- 
riod of  life  can  the  lunglets  be  best  seen  ? 

n* 


248 


HITCHCOCK’S  A N A T O ]^r  Y 


hexagonal  figure  surrounding  the  bronchial  tube,  shows  a 
section  of  a lun^let,  or  lobule  of  the  lunn;. 

438.  The  Pleura. — Pleurisy. — Root  of  the  Luugs. — The 
lungs  are  immediately  invested  with  a serous  membrane  called 
the  Pleura,  which  is  also  the  inner  lining  membrane  of  the 
walls  of  the  chest : so  that  when  the  lungs  are  fully  inflated, 
these  two  surfaces  are  brought  in  contact,  and  in  the  act  of 
respiration  move  slightly  upon  each  other.  And  if  any  por- 
tion of  these  membranes  becomes  inflamed,  the  disease  results 
which  is  known  as  Pleurisy.  In  the  acute  or  early  stage  of 
this  disease,  if  a long  breath  be  drawn,  intense  pain  is  felt  at 
the  lower  portion  of  the  lung.  This  is  owing  to  the  friction 
of  these  inflamed  membranes  one  upon  the  other,  and  the 
reason  why  the  pain  is  severest  in  the  lower  part  of  the  lang, 
is  that  this  part  of  the  lung  moves  over  the  largest  space  in 
breathing.  The  vessels  for  supplying  blood,  emptying  it 
and  nourishing  the  lungs,  as  well  as  the  air-vessels,  nerves 
and  lymphatics,  are  all  collected  together  in  one  bundle  at 
the  inner  side  of  these  organs,  and  are  collectively  called  the 
Root  of  the  Lungs. 

439.  Tlie  Air  Passages. — The  vessels  wdiich  are  especially 
designed  for  the  purpose  of  conveying  air  into  the  lungs  are 
the  Larynx,  from  the  Greek  meaning  a whistle,  since  sound 
is  made  in  it — the  Trachea,  meaning  rough,  as  is  its  struc- 
ture— the  Bronchia,  meaning  the  windpipe,  (Fig.  250,  p. 
249),  and  the  intercellular  passages  which  terminate  in  the 
air-cells.  (Fig.  252,  p.  250.) 

440.  The  Larynx. — The  Larynx  is  a conical  cartilaginous 
tube  from  one  to  two  inches  in  diameter,  opening  upwards  into 
the  Pharynx,  and  terminating  below  in  the  Trachea.  (See 
Organs  of  Voice.) 

441.  Tlic  Trachea. — The  Trachea  is  a cartilaginous  tube 


43ft.  Wliat  arc  tlio  lunf's  covered  wi til,  and  what  is  the  chest  lined  with?  What  is 
rienrisy  ? What  is  meant  by  the  root  of  the  lung?  439.  Give  the  names  of  the  dif- 
fwrent  jiarts  of  tho  air-passages.  410.  Describe  the  Larynx. 


AND  PHYSIOLOGY 


249 


Fig.  250. 


The  Larynx,  Trachea,  and  Bronchia,  deprived  of  their  Fibrous  Coverin",  and  with  the 
outline  of  the  Lungs.  1,  1,  Outline  of  the  Upper  Lobes  of  the  Lungs.  2,  Outline  of  the 
the  Middle  Lobe  of  the  Right  Lung.  3,  3,  Outline  of  the  Inferior  Lobt-s  of  both  Lungs. 
4,  Outline  of  the  Ninth  Dorsal  Vertebra,  showing  its  relation  to  the  Lungs  and  the  Ver- 
tebral Column.  5,  Thyroid  Cartilage.  6,  Cricoid  Cartilage.  7,  Trachea.  8,  Right 
Bronchus.  9,  Left  Bronchus.  10,  Crico-Thyroid  Ligament.  11,  12,  Rings  of  the  Tra- 
chea. 13,  First  Ring  of  the  Trachea.  14,  Last  Ring  of  the  Trachea,  which  is  Corset- 
shaped. 15, 16,  A complete  Bronchial  Cartilaginous  Ring.  17,  One  which  is  Bifurcated. 
18,  Double  Bifurcated  Bronchial  Rings.  19,  19,  Smaller  Bronchial  Rings.  20,  Depres- 
sions for  the  Course  of  the  large  Blood-Vessels. 

about  one  inch  in  diameter,  made  up  of  from  fifteen  to  twenty 
cartilaginous  rings,  commencing  at  a point  nearly  opposite 
the  fifth  cervical  vertebra,  and  extending  as  low  as  the  second 
dorsal,  or  top  of  the  sternum,  where  it  divides  into  two  bron- 
chi extending  to  each  lung.  These  segments  of  the  trachea 
are  not  perfect  rings,  since  they  complete  only  about  five  sixths 


441.  How  is  the  trachea  made  up  ? Where  does  it  divide  into  the  two  bronchi  ? Ar« 
the  segments  of  the  trachea  perfect  rings  ? 


250 


HITCHCOCK’S  ANATOMY 


FlO.  251. 


Capillaries  of  the  Human  Lung. 


of  a circle,  the  remainino;  sixth  consistinn;  of  smooth  or  invol- 

7 0 O 

untary  muscular  fiber. 

442.  The  Bronchi. — Intercellular  Passages. — Caeca) 
Air-Cells.  Their  Number. — As  soon  as  the  Bronchi  fairly 

Fig.  252. 


A Magnified  View  of  a Section  of  the  Lung,  showing  the  Arrangement  of  some  of 
the  Lobules,  the  Communication  of  the  Air-Cells  in  one  Lobule  and  their  Separation 
from  those  of  the  adjoining  L<d)ulo.  The  Mainifications  of  the  Blood-Vessels  in  the 
Texture  of  the  Lung  and  their  Course  through  the  Air-Cells  are  also  seen.  1,  1, 
Branches  of  tho  I’ulmonary  Veins.  2,  2.  Branches  of  the  rulmonary  Artery. 


AND  PHYSIOLOGY. 


251 


enter  the  lungs,  they  immediately  divide  and  subdivide,  until 
they  have  diminished  to  a diameter  about  one  fiftieth  of  an 
inch,  and  some  of  them  are  within  one  eighth  of  an  inch  of 
the  outside  of  the  lung.  After  this  they  are  changed  in  their 
structure,  and  become  channels  hollowed  out  in  the  cellular 


tissue  of  the  lung,  and  are 
These  terminate  in  minute 
cells,  called  Caecal  Air-Cells. 
These  cells  have  an  average 
diameter  of  yloth  of  an  inch, 
and  accumulate  around  each 
terminal  bronchus  to  the  num- 
ber of  17,790,  making  a total 
in  the  lungs  of  600,000,000, 
which,  if  spread  out,  would 
make  an  area  of  cell  surface 
of  132  square  feet;  Dalton 
says  1,400  square  feet. 

443.  Composition  of  the 
Air-Tuhes.  Their  Mucous 
and  Pleural  Surfaces. — 
These  air-tubes  just  described 
are  essentially  composed  of 
cartilage  and  fibro-cartilage, 
and  lined  throughout  with 
mucous  membrane.  Hence 
we  see  that  this  membrane, 
though  situated  nearest  the 
center  of  the  body,  lines  the 
outside  of  the  lungs,  while 
the  Pleura,  although  nearer 
the  surface  of  the  body,  lines 


called  Intercellular  Passages. 

Fig.  253. 

1 


Longitudinal  Section  of  tlio  Termina- 
tion of  a Bronchus.  1,  Bronchus.  2,  Cae^ 
cal  Air-Cell.  3,  Orifice  of  the  same. 


Fig.  254. 


Small  Bronchial  Tube  laid  open. 


442.  What  are  the  bronchial  tubes  subdivided  into?  IIovv  large  are  the  caecal  air-cellsl 
How  many  around  each  terminal  bronchus?  What  is  their  aggregate  number?  What 
is  the  area  of  cell  surface  in  the  lungs?  443.  What  is  the  composition  of  the  air-tubes  ? 
Which  is  really  thejnside  and  which  the  outside  of  the  lungs? 


252  HITCHCOCK’S  anatomy 

the  interior  of  the  lungs.  This  apparent  contradiction  of 
terms  arises  from  considering  that  portion  of  the  body  as  ex- 
ternal which  is  in  contact  with  the  air,  in  the  same  manner  as 
the  intestines  ; the  anatomically  external  surface  being  phys- 
iologically the  internal  surface. 

444.  The  Substance  of  the  lungs, — The  substance  of  tlie 
lungs  is  entirely  made  up  of  arteries,  veins,  lymphatics,  and 
bronchial  tubes,  connected  by  areolar  tissue.  And  when  in- 
flammation takes  place  in  this  substance,  the  disease  is  known 
as  pneumonia,  or  lung  fever. 

445.  The  Essential  Muscle  of  Respiration — Process  of 
Brcatliing — The  Rest  Gained  by  the  Respiratory  Muscles 
— The  muscle  which  performs  the  most  essential  part  of 
breathing  is  the  diaphragm.  This  by  its  contraction  produces 
inspiration,  but  does  not  directly  produce  expiration.  Breath- 
ing is  -performed  as  follows.  The  cavity  of  the  chest  is  va- 
riable in  size ; made  so  by  the  movement  of  the  diaphragm 
Upwards  and  downwards.  For  as  the  sides  and  upper  portion 
of  the  chest  are  unyielding  walls,  if  the  diaphragm  be  de- 
pressed the  cavity  of  the  chest  is  enlarged,  a partial  vacuum 
is  produced,  and  the  air  rushes  in  to  supply  the  vacancy. 
This  is  inspiration,  and  is  purely  an  active  muscular  efibrt. 
Expiration,  however,  is  quite  the  reverse,  being  wholly  a pas- 
sive exercise.  For  when  the  lungs  are  filled,  the  contents  of 
the  abdomen  are  depressed  by  the  descending  diaphragm  and 
the  ribs  are  elevated,  both  of  which  parts  offer  resistance  to 
the  inhaling  force.  Consequently,  when  the  diaphragm  and 
the  other  respiratory  muscles  are  relaxed,  several  muscles  of 
the  back,  abdomen,  and  chest,  by  their  elastic  tonicity,  force 
air  again  out  of  the  mouth,  which  completes  the  process  of 
expiration  without  expending  any  nervous  energy,  and  at  the 
same  time  gives  rest  to  the  muscles  employed  in  breathing. 
Hence  the  muscles  of  respiration  are  not  all  the  time  in  ac- 


444.  Wluit  Is  llio  substance  of  the  lung  composed  of?  Dofine  pneumonia.  445.  What 
Is  the  principal  muscle  of  respiration?  Describe  the  mechanism  of  breathing.  Which 
act  Is  aetivc  and  wlilch  is  passive  ? When  do  the  respiratory  muscles  rest  ? 


AND  PHYSIOLOGY. 


253 


tion,  but  as  the  period  occupied  by  expiration  is  longer  than 
that  of  inspiration,  consequently  they  rest  during  a longer 
time  than  they  are  in  action. 


FUNCTIONS  OF  THE  LUNGS. 

446.  The  First  Object  of  Breathing. — The  immediate 
object  of  breathing  is  to  bring  air  into  the  lungs  and  carry 
it  out  again  after  it  has  performed  its  office ; and  the  function 
of  the  lungs  is  to  expose  as  large  a surface  of  blood  as  possible 
to  the  air  inhaled.  The  ultimate  objects  of  this  arrangement 
are  to  remove  waste  products  from  the  body,  which  exist  in 
the  form  of  carbonic  acid  and  water,  and  also  to  generate  the 
animal  heat  necessary.  A third,  but  by  no  means  an  incon- 
siderable value  of  this  function,  is  to  convert  the  gluten  of 
vegetable  food  into  fibrin. 

447.  Another  Use  of  Breathing,  Purifying  the  Blood 
— Endosmose  and  Exosmose.— The  impurities  of  the  blood 
— carbonic  acid  and  water — are  exchanged  for  the  oxygen  of 
the  atmosphere.  This  is  not  effected  by  actual  contact  of 
blood  and  air,  but  through  an  intervening  membrane,  the 
wall  of  the  air-cells.  It  is  a remarkable  property  of  mem- 
branes, both  animal  and  vegetable,  called  Imbibition,  or  En- 
dosmose and  Exosmosc,  that  allows  fluids  and  gases  to  pass 
through  them  in  opposite  directions  at  the  same  time. 
Through  the  membrane  of  the  lungs,  the  carbonic  acid,  which 
has  more  affinity  with  pure  air  than  for  the  blood,  passes  out- 
wards, while  the  pure  air,  containing  oxygen,  has  an  affinity 
for  the  blood,  and  passes  inwards. 

448.  Amount  of  Air  Used  in  Breathing — Causes  of  its 
Variation — Capacity  of  the  Chest. — The  average  amount 
of  air  which  passes  in  and  out  of  the  lungs  at  each  inspiration 


446.  What  is  the  object  of  breathing,  and  what  is  the  function  of  the  lungs?  W'hat 
three  processes  are  accomplished  by  this  process?  447.  How  does  breathing  purify  the 
blood  ? Describe  the  process  of  imbibition. 


254 


HITCHCOCK’S  ANATOMY 


and  expiration  is  about  twenty  cubic  inches,  and  the  amount 
passed  through  them  in  twenty-four  hours  about  360  cubic 
feet,  or,  as  others  estimate  it,  from  3,000  to  5,000  gallons 
every  day.  This  varies  greatly.  In  the  first  place,  the  lower 
the  temperature  the  greater  the  amount  of  animal  heat  to  be 
generated,  and  consequently  the  greater  the  quantity  of  air 
to  be  consumed.  Also  a person  laboring  in  the  open  air 
breathes  more  deeply  than  one  confined  to  the  house.  Again, 
the  capacity  of  the  lungs  modifies  the  quantity  of  air  inhaled. 
And  this  capacity  depends  more  upon  the  height  of  the  indi- 
vidual than  any  other  physical  feature.  From  a series  of 
5,000  observations  made  by  Dr.  Hutchinson,  the  following 
principle  is  deduced.  For  every  inch  of  stature  from 
five  to  six  feet,  eight  additional  cubic  inches  of  air  are  given 
out  at  a forced  expiration  after  a full  inspiration.’’  That  is, 
if  a person  five  feet  and  six  inches  in  height  can  expire  422 
cubic  inches,  a person  five  feet  and  seven  inches  can  expire 
430  cubic  inches. 

449.  Effect  of  Corpulence  on  Capacity  of  lungs. — 
Another  fact  of  importance  is  deduced  by  the  same  experi- 
menter— that  if  a person  exceed  the  average  weight  on  ac- 
count of  corpulence,  the  capacity  of  the  lungs  decreases  in  a 
marked  ratio,  as  is  stated  in  these  words  : ‘‘  When  the  man 
exceeds  the  average  weight  (at  each  height)  by  7 per  cent,  the 
vital  capacity  decreases  one  cubic  inch  per  pound  for  the  next 
thirty-five  pounds  above  that  weight.” 

450.  Function  of  the  Red  Corpuscles. — The  red  cor- 
puscles of  the  blood  seem  to  be  the  carriers  of  oxygen  from 
the  lungs  to  the  various  parts  of  the  body.  The  prominent 
reason  for  this  belief  is  that  the  serum  and  salts  of  the  blood 
have  but  a very  slight  power  of  absorbing  oxygen,  while  the 
discs  condense  this  gas  at  once. 

448.  How  rmicli  air  is  used  in  each  act  of  inspiration,  and  how  much  each  day  ? IIow 
docs  tcitjporaturo  and  ex[K)suro  to  the  open  air  affect  the  amount  respired  ? Upon  what 
docs  the  capacity  of  the  lungs  depend  ? Give  the  law  and  its  example.  449.  IIow  does 
corpulence  affect  the  capacity  of  the  chest  ? Give  the  formula.  450.  What  is  the  prob- 
able function  of  the  rod  corpuscles  of  the  blood  ? 


AND  PHYSIOLOGY. 


255' 


451.  Inspirations  compared  with  Pulsations— Quan- 
tity of  Watery  Vapor  Given  off  in  Twenty-four  Hours — 
Amount  of  Carbonie  Acid  Exhaled — The  Amount  of  Solid 
Carbon  given  off. — If  we  compare  the  number  of  inspira- 
tions in  a minute  with  the  pulsations  of  the  heart,  we  shall 
find  the  proportion  of  the  former  to  the  latter  is  as  one  to 
four  or  five  in  the  human  adult.  Every  fifth  breath  is  usually 
deeper  than  the  preceding  four,  and  the  time  occupied  by 
each  respiratory  act  is  about  three  and  a half  seconds ; and 
all  the  blood  in  the  body  (when  in  vigorous  exercise)  probably 
is  exposed  to  the  air  in  the  lungs  every  two  minutes. 

The  quantity  of  watery  vapor  which  is  ordinarily  exhaled 
from  the  lungs  in  twenty-four  hours  ranges  from  sixteen  to 
twenty  ounces.  The  amount  of  carbonic  acid,  however,  varies 
much  more,  being  from  one  to  three  pounds  in  twenty-four 
hours,  and  the  causes  of  variation  are  temperature,  age,  sex, 
state  of  health  or  disease,  development  of  the  body,  muscular 
exertion  or  repose,  sleep  or  watchfulness,  and  period  of  the 
day.  This  gas  (carbonic  acid)  contains  in  every  100  pounds 
28  pounds  of  carbon  (charcoal)  and  72  pounds  of  oxygen 
(gas).  Hence  the  weight  of  carbon  which  escapes  in  this 
form  from  the  lungs  of  a full-grown  man  varies  from  five  to 
fifteen  ounces  in  twenty-four  hours.’’ 

452.  Respiration  as  a Source  of  Animal  Heat. — The 
value  of  the  function  of  breathing  as  a means  of  producing 
animal  heat,  will  be  considered  under  the  organs  for  produc- 
ing heat. 

453.  Changes  in  the  Food  effected  by  Respiration. — 
A third  object  of  breathing  is  to  efiect  such  changes  in  the 
food  that  it  can  be  directly  converted  into  the  different  tissues 
of  the  body.  Hence  the  oxygen  of  the  air  is  a part  of  the 
food  that  we  live  upon.  For  although  the  gluten  which  is  so 

451.  What,  is  the  relative  number  of  inspirations  and  pulsations  of  the  heart?  What 
length  of  time  is  occupied  in  breathing?  What  quantity  of  vapor  of  water  is  exhaled  in 
twenty -four  hours,  and  what  amount  of  carbonic  acid?  Hoav  is  this  amount  modified  ? 
What  weight  of  carbon  or  charcoal  is  given  out  of  the  body  by  the  lungs  every  day? 
453.  What  effect  has  the  oxygen  of  the  air  upon  the  glutinous  portion  of  our  food  ? 


25G 


HITCHCOCK’S  ANATOMY 


largely  contained  in  vegetable  food  very  closely  resembles 
fibrin  (which  is  the  form  that  the  nutrient  |)ortion  of  the*  food 
must  be  in  before  it  can  nourish  the  greater  part  of  the  body, 
and  especially  the  muscles),  still  chemical  analysis  shows  that 
the  gluten  must  receive  another  equivalent  of  oxygen  before 
it  is  fitted  to  reproduce  the  different  tissues  of  the  body.  And 
the  only  way  in  which  this  oxygen  can  be  given  to  the  body 
is  either  through  the  lungs  or  skin. 

454.  Amount  of  Air  which  the  lungs  can  Contain. — 
The  amount  of  air  which  the  lungs  actually  do  contain  is-  l)y 
no  means  the  amount  that  should  be  actually  supplied  to  them. 
For  the  air  which  surrounds  the  body  is  very  rarely  indeed 
perfectly  pure,  but  is  contaminated  with  the  previously  ex- 
haled breath,  on  account  of  the  law  of  diffusion  oF  gases, 
which  is,  that  when  two  gases  are  brought  into  contact  they 
immediately  commingle  with  each  other.  Experiment  shows 
that  between  350  and  400  cubic  feet  of  air  are  actually  ex- 
haled during  the  twenty-four  hours  ; but  experience  shows 
that  the  least  quantity  which  should  be  allowed  for  dwelling- 
houses,  shops,  and  school-houses,  should  be  800  feet  in  order 
to  furnish  a sufficient  supply  of  oxygen. 


CALORIFIC  ORGANS. 

455.  lleat-produciiig  Organs — Theory  of  Animal  Heat. 
— The  organs  which  produce  animal  heat  are  essentially  those 
employed  in  the  act  of  breathing  and  the  circulation  of  the 
blood,  and  consequently  already  explained,  but  the  actual 
method  by  which  it  is  produced  has  for  a long  time  perplexed 
physiologists.  The  theory  which  now  is  most  readily  accepted 
makes  the  function  to  be  a chemico-vital  one,  or  a chemical 


What  is  that  element  wliich  principally  nourishes  the  muscles?  454.  What  is  the  law 
of  diffusion  of  gases,  and  what  modifying  Inlluenco  does  this  have  on  tlic  hygiene  of  res- 
j)iration  ? flow  many  cubic  feet  of  air  should  be  allowed  to  every  in-door  laborer  or 
student?  45.5.  What  are  the  heat-producing  organs?  What  is  at  present  the  most 
readily  accepted  theory  of  animal  heat? 


AND  PHYSIOLOGY. 


257 


change  (oxydization)  dependent  upon  vital  energy,  being 
nearly  analogous  to  the  burning  of  a candle  or  the  combus- 
tion of  wood  and  coal  in  the  stove. 

456.  Process  of  Producing  Animal  Heat. — As  the  oxy- 
gen in  the  inspired  air  enters  the  lungs  and  is  brought  into 
contact  with  the  blood  through  the  wall  of  the  air-cells,  the 
carbon  of  the  venous  blood  unites  with  it,  forming  carbonic 
acid,  and  heat  is  generated.  This  is  precisely  the  same  thing 
that  takes  place  in  the  furnace,  where  the  air  enters  through 
the  draft  supplying  the  oxygen,  and  the  coal  furnishes  the 
carbon,  the  result  of  the  union  being  heat.  But  it  is  not  in 
the  lungs  alone  that  this  heat  is  generated  : for  we  have  al- 
ready seen  that  the  blood  is  highly  charged  with  oxygen  as  it 
passes  through  the  arteries  to  the  various  organs  of  the  body. 
And  as  it  passes  through  the  capillaries  in  every  part  of  the 
system,  it  there  receives  an  equivalent  of  carbon,  the  w^aste 
of  the  system  producing  carbonic  acid,  in  which  operation 
heat  is  given  off.  Hence  we  see  that  heat  is  generated  not 
only  in  the  lungs  but  in  every  part  of  the  body,  and  that  it 
is  incessantly  being  produced,  which  is  a reason  why  the  ex- 
tremities of  the  body  are  constantly  kept  at  their  proper  tem- 
perature ; for  if  all  the  heat  were  to  be  generated  in  the  lungs, 
very  frequently  the  blood  would  become  chilled  in  its  passage 
to  the  extreme  capillaries.  We  also  see  that  forced  respira- 
tion has  the  same  effect  as  increasing  the  draft  of  air  into 
the  furnace,  and  that  the  fuel  of  the  human  system  is  sup- 
plied by  means  of  the  food  placed  in  the  stomach. 

457.  Temperature  of  Human  Body. — The  temperature  of 
the  human  system  is  98°  F.,  and  this  it  is  invariably  found  to 
be  in  all  climates  and  seasons  when  the  individual  is  in  pos- 
session of  perfect  health.  So  that  in  most  climates  the  tem- 
perature of  the  body  is  above  that  of  the  surrounding  atmos- 


456.  Describe  tbe  process.  Is  all  the  lieat  of  the  body  generated  in  the  lungs  ? Where 
in  the  body  is  it  no^  generated  ? What  is  the  fuel  of  the  body?  Where  is  the  draft? 
457.  What  is  the  temperature  of  the  human  body?  How  is  the  heat  of  the  body  com- 
pared with  that  of  nearly  all  climates? 


258  HITCHCOCK’S  ANATOMY 

pliere,  and  we  are  constantly  giving  off  heat  to  the  air  which 
envelops  us. 

458.  Manner  in  which  the  Body  is  maintained  at  its 
uniform  Temperature. — The  manner  in  which  the  body  is 
kept  at  the  uniform  temperature  of  98°,  is  a subject  of  deep 
interest.  It  is  partly  accomplished  by  radiation,  since  the 
body  is  ordinarily  warmer  than  the  air  about  it,  and  also 
partly  by  inhaling  the  cool  air  into  the  air  passages.  It  is  a 
well-known  principle  in  chemistry,  that,  when  any  substance 
passes  from  a more  solid  to  a less  solid  condition,  as  from 
solid  to  liquid,  or  liquid  to  a gas,  heat  is  absorbed,  or,  in  more 
common  lan^ua^e,  cold  is  made  sensible.  This  is  seen  in  the 
application  of  water,  alcohol,  or  ether,  to  the  skin,  when  a 
sensation  of  cold  is  felt,  which  is  owing  to  the  fact  that  the 
substance  applied  is  passing  from  the  form  of  a liquid  to 
that  of  a vapor.  Now  the  same  thing  takes  place  when  the 
perspiration  is  allowed  to  evaporate  from  the  surface  of  the 
body.  The  increased  flow  of  blood,  as  brought  about  by  the 
exercise,  or  the  high  temperature  of  the  surrounding  at- 
mosphere, stimulates  the  vessels  of  the  skin  to  more  energetic 
action,  and  sensible  perspiration  is  poured  out  upon  the  sur- 
face of  the  body.  This,  however,  is  now  in  contact  with  the 
currents  of  air  always  present  about  the  body,  and  it  is  readily 
thrown  out  into  a state  of  vapor,  and  in  accordance  with  the 
chemical  principle  just  stated,  heat  is  absorbed  from  the  body 
producing  its  uniform  temperature. 

458a.  It  should  be  mentioned  here,  that  of  late  many 
experiments  have  been  carried  on  which  seem  to  show  us 
that  the  above-mentioned  theory  of  animal  heat  can  not  be 
fully  adopted.  For  it  is  well  known  that  many  chemical 
combinations  besides  those  of  mere  oxydation  or  burning” 
produce  heat;  and  many  of  these  processes  are  constantly 
taking  place  in  the  body.  But  all  the  facts  hitherto  ad- 


4r)8.  How  is  the  body  kopt  ut  its  uniform  tomporaturo ? What  chemical  principle 
illustrates  this  view  ? 4138a.  Give  the  result  of  recent  experiments. 


AND  PHYSIOLOGY. 


259 


vanced  do  not  by  any  means  entirely  overthrow  the  old  theo- 
ry. They  show  us  that  the  theory  of  combustion  does  not 
cover  the  whole  ground,  but  that  other  causes,  as  well  as 
oxydation  produce  animal  heat.  And  we  propose  the  idea 
that  animal  heat,  like  digestion,  is  a chemico-vital  process, 
that  is,  a process  under  the  immediate  influence  of  chemical 
changes,  but  entirely  under  the  control  of  the  vital  principle, 
since  animal  heat  can  not  be  maintained  after  death. 




ORGANS  OF  THE  VOICE. 

DEFINITIONS  AND  DESCRIPTIONS. 


459.  The  Larynx;  its 
Cartilages. — The  Larynx  in 
all  animals  is  the  essential  or- 
gan for  the  production  of  the 
voice.  It  has  also  very  much 
the  same  structure  in  every 
animal  which  has  the  power  of 
expressing  its  feelings  by  the 
voice.  A cartilaginous  tube, 
imperfectly  conical,  the  base 
directed  upwards,  made  up 
of  distinct  portions  or  seg- 
ments slightly  movable  upon 
one  another,  and  with  a cer- 
tain portion  of  the  channel 
lengthened  into  a narrow  and 
elongated  opening,  constitutes 
a larynx.  In  man  this  organ 
is  made  up  of  seven  distinct 
portions  or  cartilages,  two 
Arytenoid  (pitcher-shaped). 


Fig.  255. 


A Lateral  View  of  the  Larynx.  1,  Os 
Ilyoides.  2,  Thyreo-Hyoid  Ligaments. 

3,  Cornu  Majus  of  the  Thyroid  Cartilage. 

4,  Its  Angle  and  Side.  5,  Cornu  Minus. 
6,  Lateral  Portion  of  the  Cricoid  Carti^ 
lage.  7,  Rings  of  the  Trachea. 


260 


HITCHCOCK’S  ANATOMY 


two  Cuneiform  (wedge-shaped),  one  Cricoid  (ring-like),  one 
Thyroid  (shield-like,)  and  one  Epiglottis  (cover  to  the  Glottis). 
These  together  form  the  small  prominent  portion  of  the  neck 
known  as  Adam's  apple. 

460.  Thyroid  Cartilage. — Arytenoid  Cartilages. — Cu- 
neiform Cartilages.— Cricoid  Cartilage.— Vocal  Cords.— 
Ventricle  of  the  Larynx.— Muscles  of  the  larynx.— The 
Thyroid  Cartilage  is  so  arranged  as  to  form  a framework  for 
the  movable  portions  of  the  organs  of  the  voice,  and  this  is 
the  principal  cartilage  that  forms  the  Adam’s  apple.  The 
Arytenoid  Cartilages  can  be  moved  by  the  small  muscles  of 


Fig.  25G. 


A Front  View  of  the  Thyroid  Carti- 
lage. 1,  Left  Half  of  the  Cartilage.  2, 
Anterior  projecting  Angle.  3,  Superior 
Margin.  4,  Its  Notch.  5,  Inferior  Margin. 
6,  G,  Cornua  Majora.  7,  7,  Cornua  Minora. 


Fig.  257. 


A Posterior  View  of  the  Left  Arytenoid 
Cartilage.  1,  Its  Posterior  Face.  2,  The 
Summit.  3,  The  Base  and  Cavity  for 
Articulating  with  the  Cricoid  Cartilage. 
4,  Its  External  Angle.  5,  Its  Internal 
Angle. 


the  larynx.  The  object  of  this  movement  is  to  relax  or 
tighten  the  vocal  cords,  so  that  the  different  pitch  and  quality 
of  voice  may  be  perfected.  The  Cuneiform  Cartilages  are 
a])out  half  an  inch  in  length,  and  enlarged  at  each  extremity. 
These  are  sometimes  wanting.  The  Cricoid  Cartilage  is  of  a 
ring-like  appearance,  and  resting  directly  upon  the  rings  of 


459.  What  is  the  essential  organ  of  voice  in  all  animals?  Give  the  anatomy  of  the 
larynx.  Name  the  seven  cartilages.  400.  Describe  the  thyroid  and  arytenoid  cartilages. 
Describe  the  cuneiform  and  cricoid  cartilages. 


AND  PHYSIOLOGY 


261 


the  trachea,  being  of  a little  longer  diameter  than  the  trachea. 
The  Epiglottis  is  the  most  movable  of  all  the  vocal  cartilages.* 

Fig.  258.  PiG.  259. 


A Front  View  of  the  Cricoid  Cartilage. 
1,  Its  Internal  Face.  2,  The  Cavity  of 
the  Larynx  as  formed  hy  this  Cartilage. 
3,  Its  Inferior  Surface.  4,  The  little  Head 
or  Convexity  for  Articulating  with  the 
Arytenoids.  5,  The  Surface  of  the  Su- 
perior Edge  for  the  Attachment  of  the 
Lateral  Crico-Arytenoid  Muscles. 


A Lateral  View  of  the. Epiglottis  Carti- 
lage. 1,  Anterior  or  Convex  Surface.  2, 
Posterior  or  Concave  Surface.  3,  Superior 
Margin.  4,  Inferior  Margin  or  Pedicle. 
5,  Its  Sides.  The  Openings  of  the  Muci- 
parous Ducts  are  also  shown. 


Fig.  260. 


It  in  shape  resembles  a cord- 
ate or  heart-shaped  leaf,  at- 
tached by  its  apex  to  the  up- 
per edge  of  the  glottis,  and 
has  a wide  range  of  motion, 
in  order  to  completely  close 
up  the  passage  into  the  lungs, 
or  leave  a free  communica- 
tion between  them  and  the 
air.  It  also  aids  in  deaden- 
ing sounds,  as  it  is  suddenly 
brought  down  upon  the  glot- 
tis. All  these  cartilages  very 


12 

A Posterior  View  of  the  Articulations  of  the  Cartilages  of  the  Larynx.  1,  Posterior 
Face  of  the  Epiglottis.  2,  Appendices  of  the  Os  Hyoides.  3,  Its  Cornua.  4,  Lateral 
Thyreo-IIyoid  Ligaments.  5,  Posterior  Face  of  the  Thyroid  Cartilage.  6,  Arytenoid 
Cartilages.  7,  Cricoid  Cartilage.  8,  Crico-Arytenoid  Articulation.  9,  Posterior  Crico- 
Thyroid  Ligament.  10,  Cornu  Minus  of  the  Thyroid  Cartilage.  11,  Anterior  Crico- 
Thyroid  Ligament.  12,  Ligamentous  Portion  of  the  first  King  of  the  Trachea. 


262 


HITCHCOCK’S  ANATOMY 


frequently  become  considerably  ossified  in  males  in  ad- 
vanced age. 

The  Vocal  Cords  or  ligaments  are  folds  of  white  fibrous  tis- 
sue, covered  by  mucous  membrane,  and  are  made  to  vibrato 
when  the  air  is  forced  over  them.  Hence  ulceration,  or  any 


Fig.  261. 


A View  of  the  Larynx  from  above, 
showing  the  Thyreo- Arytenoid  or  Vocal 
Ligaments.  1,  Superior  Edge  of  the  La- 
rynx. 2,  Its  Anterior  Face.  3,  Cornua 
Majores  of  the  Thyroid  Cartilage.  4,  Pos- 
terior Face  of  the  Cricoid  Cartilage.  5,  5, 
Arytenoid  Cartilages.  6,  6,  Thyreo-Ary- 
tenoid  Ligaments.  7,  Their  Origin  within 
the  Angle  of  the  Thyroid  Cartilage.  8, 
Their  Terrninations  at  the  Base  of  the 
Arytenoid  Cartilages.  9,  The  Glottis.  10, 
Anterior  Part  of  the  Inferior  Surface  of 
the  Cricoid  Cartilage. 


Fig.  262. 


i 

} 

: 


i 

Muscles  of  Human  Larynx.  (?.  E.  H, 
Thyroid  Cartilage,  r.  w.  X.  w.  Cricoid. 
JV  F.  Arytenoid.  T.  V.  Vocal  Ligaments. 
JV,  X.  V.  K.  f.  and  N.  1.  Muscles  of  La- 
rynx. 


alteration  in  the  structure  of  these  cords,  will  produce  hoarse- 
ness, a loss  of  intonation — a whispering — or  some  change  in 
the  quality  of  the  voice.  The  cords  just  mentioned  are  not, 
however,  the  only  ones  that  exist  in  the  larynx,  for  these  are 
the  upper  ones,  while  another  pair  called  the  inferior  cords, 
exist  below  the  others,  leaving  a cavity  known  as  the  ventricle 
of  the  larynx,  (Fig.  263,  p.  263),  which  seems  essential  to 
the  proper  production  of  sound : although  there  is  nothing 
analogous  to  it  in  the  ordinary  musical  instruments.  The 
muscles  connected  with  the  larynx  are  eight:  five  of  them 

AVhat  is  tlio  epiglottis?  Of  what  arc  the  vocal  cords  composed?  What  is  the  ven- 
tnclo  of  the  larynx  ? How  many  muscles  belong  to  the  larynx  ? 


AND  PHYSIOLOGY. 


26? 


Fig.  263. 


Cartilages  of  Larynx  and  Epiglottis,  a.  Arytenoid,  h.  Its  Superior  Cornu,  c.  In- 
ferior Cornu,  d.  Cricoid.  /.  Perforation  of  Epiglottis,  i.  Upper  Part  of  Thyroid. 
t.  Trachea,  h.  Tubercle. 

pass  between  the  different  cartilages,  and  are  of  use  in  regu- 
lating the  size  of  the  glottis  and  the  tension  of  the  vocal  cords, 
while  the  three  remaining  go  from  the  epiglottis  to  the  dif- 
ferent parts  of  the  larynx,  solely  for  the  purpose  of  moving 
this  valve  to  aid  in  articulation  and  closure  of  this  passage  to 
the  lungs. 


Which  move  the  cartilages,  and  which  are  distributed  mainly  t®  the  epiglottis  ? 

12 


264 


HITCHCOCK’S  ANATOMY 


FUNCTIONS  OF  THE  LARYNX. 

461.  Similarity  of  the  Larynx  to  a Rccd  Instrument,— 
The  larynx,  as  an  organ  of  sound,  very  much  resembles  a 
reed  instrument,  or  the  reed  pipes  in  an  organ.  For  we 
have  the  reed,  or  rather  the  reeds,  in  the  vocal  cords,  and  the 
column  of  air  in  the  pharynx  and  mouth.  This,  however, 
differs  from  the  proper  reed  instrument  by  the  vibration  of 
free  edges  of  the  reed,  and  also  by  the  power  of  tightening  or 
relaxing  the  cords  to  produce  different  pitches  of  tone  ; for  in 
the  hautboy,  bassoon,  and  similar  instruments,  the  tone  is 
regulated  by  the  length  of  the  vibrating  column  of  air,  which 
is  controlled  by  the  keys  and  finger-holes. 

462.  Use  of  the  Cartilages. — The  arrangement  of  the 
cartilages  of  the  larynx  is  such  as  to  give  form  and  stability 
to  the  organ,  and  at  the  same  time  a firm  attachment  to  the 
vocal  cords,  muscles,  and  ligaments.  In  male  adults  these 
are  much  larger  than  in  females,  since  the  voice  of  the  former 
is  heavier  and  of  a much  lower  tone  than  that  of  the  latter, 
requiring  greater  length  of  vocal  cord,  and  consequently 
firmer  points  of  attachment. 

463.  Organs  Essential  for  tnc  Production  of  mere 
Sound . — The  vocal  cords,  together  with  the  diaphragm,  ab- 
dominal muscles,  and  lungs,  are  all  the  organs  which  are 
necessary  for  the  production  of  sound.  But  the  quality  of 
sound  and  articulation  are  produced  and  modified  very  essen- 
tially by  other  parts  of  the  body. 

464.  Use  of  the  Cavity  in  the  Frontal  Bone. — The  si- 
nus, or  cavity  in  the  frontal  bone  which  communicates  with 
the  pharynx,  is  a very  important  member  of  the  vocal  organs, 
as  it  imparts  resonance  to  the  voice  in  the  same  manner  as  the 

401.  Wliat  kind  of  instninu'nt  does  tlio  larynx  resemble?  What  correspond  to  the 
reeds?  402.  Of  what  use  arc  the  cartilaires?  Are  the  vocal  cords  longest  in  man  or 
woman  ? What  Is  the  result  of  it?  40^.  What  orj^ans  of  the  body  are  necessary  for  the 
production  o i‘ bound  ? 404.  Of  what  ute  is  the  cavity  in  the  frontal  bone  ? 


AND  PHYSIOLOGY. 


265 


hollow  portion  of  the  violin  and  violincello,  or  the  long  tube  of 
brass  instruments,  gives  the  proper  tone  to  these  instruments. 
The  want  of  such  a cavity  for  the  perfection  of  the  human 
voice  is  well  appreciated,  when  a person  is  suffering  with  a 
severe  cold  in  the  head,  as  it  is  termed.  In  this  case  the 
voice  is  of  an  extremely  nasal  character,  because  the  passage 
to  the  frontal  sinus  is  closed  up  by  a thickening  of  the  lining 
membrane,  which  prevents  a resonance  of  the  tones  made  in 
the  larynx. 

465.  Function  of  the  Nostrils  in  the  Voice. — An  open 
passage  through  the  nostrils  is  also  very  important  for  the 
production  of  perfect  tones  of  the  voice.  For  when  this  is  ob- 
structed in  any  way,  the  head  or  nasal  tone  is  invariably  pro- 
duced. 

466.  Function  of  the  Tongue  in  the  Making  of  Ar- 
ticulate Sound — Not  Absolutely  Essential.— The  tongue 
is  the  chief  organ  of  articulation,  and  in  connection  with 
the  lips  and  teeth,  the  tones  made  in  the  glottis  are  either 
lengthened  or  shortened,  and  otherwise  modified  to  form  the 
different  letters.  If  either  of  these  organs  is  deficient  in  sub- 
stance or  function,  the  articulate  sounds  are  imperfect ; as, 
for  instance,  the  letters  T,  D,  L,  F,  and  S,  which  require  a 
full  development  of  all  the  parts  for  their  perfect  enunciation. 
It  is,  however,  stated  as  a fact,  that  some  people  have  been 
known  to  articulate  words  with  distinctness  after  the  tongue 
was  removed  by  a gun-shot  wound. 

HYGIENIC  INFERENCES. 

467.  — 1.  From  the  size  of  the  lungs  we  see  that  they  are 
organs  of  great  importance  in  the  system. 

468.  — 2.  liability  of  the  lungs  to  Disease.— On  ac- 
count of  their  delicate  structure  and  constant  use,  they  are 

What  produces  the  talking  through  the  nose,  as  it  is  termed?  465.  IIow  do  the  nos- 
trils affect  the  voice  ? 466.  What  use  has  the  tongue  in  speech  ? Also  the  teeth  and 
lips?  Is  the  tongue  always  absolutely  essential?  467.  What  does  the  great  size  of  the 
lungs  show  us  ? 


266 


IT  ITC  IT  cock’s  anatomy 


liable  to  disease,  and  consequently  need  especial  care  to  keep 
them  in  health. 

469.  — 3.  Action  of  tlic  Lungs  Essential  for  tlieir 
Health. — One  important  item  to  secure  the  health  of  these 
organs,  is  to  keep  every  part  of  them  in  action.  Hence  pres- 
sure of  clothing,  or  any  thing  else  that  prevents  the  complete 
filling  of  the  lungs  by  breathing,  is  quite  sure  to  induce  dis- 
ease. For  if  but  a very  few  of  the  millions  of  air-cells  con- 
tained in  the  lungs  are  allowed  to  lie  inactive  or  useless,  na- 
ture will  attempt  their  removal  by  means  of  the  lymphatics, 
and  this  removal  is  often  the  commencement  of  fatal  disease. 
Therefore  it  is  a good  practice  for  every  one,  and  especially 
sedentary  persons,  several  times  each  day  to  throw  back  and 
downwards  the  shoulders,  and  slowly  fill  the  lungs  to  their 
utmost  capacity,  and  then  permit  the  air  to  escape  slowly,  be- 
cause in  this  way  every  cell  in  the  lungs  will  be  used. 

470.  — 4.  Pure  Air  is  Essential  to  Healthy  lungs — 
Life  Depends  on  Breathing  Pure  Air.^ — All  mechanical 
and  chemical  impurities  of  the  air  inhaled  induce  and  ag- 
gravate disease.  Indeed,  the  most  important  hygienic  rule 
for  the  lungs  is  to  breathe  pure  air.  Mechanical  impurities, 
such  as  dust  and  vapors,  are  eminently  injurious,  but  not  so 
much  so  as  the  chemical  impurity,  carbonic  acid,  which  comes 
from  the  exhalations  of  men  and  animals,  and  the  burning  of 

* Black  IIolu:  of  Calcutta. — One  of  the  most  awful  instances  of  suifocation  on  rec- 
ord, is  connected  with  what  is  known  as  the  Black  Hole  of  Calcutta.  When  Calcutta 
W'as  taken  by  the  Indian  forces,  the  British  garrison,  numbering  146  men,  were  confined 
as  prisoners  of  war  in  the  dungeon  of  the  fortress,  a room  only  eighteen  feet  square,  and 
intended  only  for  confinement  of  two  or  three  men.  This  dungeon  had  only  two  small 
windows,  both  upon  one  side  of  the  building,  in  front  of  which  was  a verandah  that  aided 
greatly  in  impeding  whatever  slight  circulation  of  air  there  might  be.  Besides  the  great 
lieat  of  a July  night,  on  which  this  occurred,  conflagrations  were  raging  near  the  fort 
which  greatly  increased  the  heat.  Very  soon  after  the  men  were  confined,  the  suffering 
became  intolerable,  and  the  dungeon  was  a scene  not  only  of  the  intensest  anguish,  but 
of  frightful  delirium  of  most  of  the  inmates.  By  eleven  o’clock  the  men  began  to  die 
very  rapidly,  and  owing  to  the  intense  heat  and  overpowering  stench  caused  by  those 
exertions  of  the  frantic  soldiers,  in  the  morning  at  six  o'clock,  when  the  doors  were 
opened,  but  twenty-three  were  alive,  who  were  either  stupefied  or  raving. 

4CS.  What  does  their  delicate  structure  show  us  ? 460.  What  is  said  of  the  necessity 
of  action  for  the  lungs  ? What  habit  is  of  great  service,  and  why  is  it  ? 470.  How  do  im- 
purities of  the  air  affect  the  lungs  ? What  kind  of  impurities  are  the  most  injurious? 
Wliat  is  one  of  the  principal  sources  of  disease  in  civilized  society  ? 


AKD  PHYSIOLOGY. 


26? 


all  combustible  substances.  And  it  is  safe  to  say,  that  the 
greater  the  care  we  take  to  ventilate  our  rooms,  and  in  every 
way  to  breathe  pure  air,  the  longer  shall  we  live  and  with 
the  least  amount  of  pain  and  disease.  Breathing  impure  air 
is  one  of  the  greatest  natural  evils  to  which  civilized  society 
is  subject,  and  destroys  more  lives  than  almost  any  other. 

471.  — 5.  We  need  Pure  Air  by  Night  as  well  as  by 
Day. — Hence  we  see  that  the  lungs  need  pure  air  all  the  time, 
by  night  as  well  as  by  day — in  the  sitting-room,  the  eating- 
room,  and  the  bed-chamber,  the  school-house,  the  meeting- 
house, rail-car,  and  steamboat,  if  we  would  do  our  utmost  to 
ward  off  disease  and  death. 

472.  — 6.  Capacity  of  the  Lungs  Affected  by  Posture, — 
The  capacity  of  the  chest  is  greatly  influenced  by  our  posi- 
tion in  sitting  or  standing,  and  the  amount  of  use  to  which 
it  is  subject.  If  the  shoulders  are  thrown  forward  or  the 
body  is  bent  in  the  same  way,  the  lungs  are  compressed,  and 
can  not  be  filled  to  their  full  capacity.  Hence  special  pains 
should  be  taken  to  maintain  the  body  in  an  erect  posture,  and 
to  keep  the  chest  thrown  forward. 

473.  — 7.  Pure  Air  is  often  a Mediciue.— In  most  diseases 
the  breathing  of  pure  air  is  important  for  restoration  to  per- 
fect health,  since  there  are  often  some  impurities  in  the  blood 
or  system  which  are  removed  mainly  by  pure  air.  So  that 
the  rule  of  supplying  pure  and  warm  air  to  the  sick  room 
should  be  rigidly  observed. 

474.  — 8.  Warm  aud  Moist  Air  the  Best  for  a Healthy 
Per  sou. — The  air  best  adapted  for  breathing  should  contain 
but  a small  amount  of  moisture,  nor  should  it  be  perfectly 
dry,  especially  that  which  comes  from  intensely  heated  iron 
surfaces.  Cold  and  damp  air  is  apt  to  bring  on  irritation  of 
the  mucous  membrane,  producing  coughs  and  colds. 

475.  — 9.  Capacity  of  the  Luugs  may  be  lucrcased.— 


471.  When  and  where  do  we  need  pure  air?  472,  IIow  is  the  capacity  of  the  lungs 
modified  ? What  of  the  necessity  of  an  erect  posture  in  sitting  or  standing  ? 473.  Why  is 
pure  air  so  important  in  sickness?  474.  What  is  the  best  quality  of  air  for  breathing? 


268 


HITCHCOCK’S  ANATOIMY 


The  lungs,  if  compressed  by  disease  or  improper  clothing,  and 
even  in  many  cases  of  so-called  perfect  health  and  soundness, 
can  be  very  much  enlarged  in  their  capacity.  This  can  be 
done  by  loud  reading,  or  by  the  simple  act  of  filling  the  lungs 
with  air  to  their  utmost  capacity  several  times  each  day,  after 
the  manner  mentioned  under  inference  3d.  If  this  healthy 
habit  be  kept  up  for  a few  years  even  by  some  considerable 
effort,  nature  will  at  length  take  up  the  habit,  and  we  shall  - 
ultimately  be  found  involuntarily  filling  the  lungs  with  pure 
air,  and  thus  fix  upon  ourselves  a hygienic  habit  of  great  im- 
portance in  preserving  health,  and  of  great  value  in  repelling 
disease. 

476.  — 10.  Colds  and  Coughs — Treatment — Sympathy 
between  the  Different  Parts  of  the  Mucous  Membrane. — 
Colds  and  ordinary  coughs  are  affections  of  the  mucous  mem- 
brane, and  generally  only  of  the  lungs,  pharynx,  and  nostrils 
and  air  passages  leading  to  the  lungs.  They  are  often  pro- 
duced by  obstructions  in  the  vessels  of  the  skin,  and  hence  a 
great  relief  in  many  instances  for  a cold,  and  often  a cure,  is 
to  remove  this  obstruction  by  stimulating  these  vessels  to 
powerful  action,  as  in  sweating.  This  effect  is  produced  by  the 
sympathy  which  exists  between  the  skin  and  mucous  mem- 
brane, one  often  performing  the  function  of  the  other  for  a 
short  time.  The  mucous  membrane  also  has  a remarkable 
sympathy  between  its  different  parts ; and  hence  even  the 
portions  which  are  unaffected  by  the  cold  should  be  kept  as 
quiet  as  possible,  by  taking,  for  instance,  but  little  food  into 
the  alimentary  canal,  and  that  of  a liquid  character,  so  that  it 
may  be  readily  taken  up  by  the  absorbents  of  the  stomach. 

477.  — 11.  Injurious  Effects  of  Wearing  Shawls  by 
Gentlemen. — From  the  fact  that  whatever  compresses  the 
chest  greatly  tends  to  bring  on  diseases  of  the  lungs,  we  in- 


475.  How  can  tho  size  of  the  lungs  bo  perceptibly  increased  ? 476.  What  are  colds  and 
common  coughs?  How  are  they  often  induced?  Whatis  their  best  treatment?  W'hat 
Is  remarkable  about  tho  sympathy  between  tho  skin  and  tho  mucous  membrane?  477. 
Uow  are  ahawla  often  injurious  to  tho  lungs  ? 


AND  PHYSIOLOGY. 


269 


fer  that  the  wearing  of  shawls  by  gentlemen,  inasmuch  as  it 
requires  a drawing  forward  of  the  shoulders  to  make  them 
thoroughly  cover  the  body,  compresses  the  lungs,  and  there- 
fore is  highly  injurious.  Moreover,  it  makes  a person  round- 
shouldered,  and  thus  gives  the  appearance  of  premature  old 
age. 

478.  — 12.  The  Neck  to  be  Dressed  lightly.— From 
the  many  movements  which  are  made  by  the  larynx  in  speak- 
ing, we  infer  that  it  is  a matter  of  great  importance  that  the 
neck  in  health  should  be  always  loosely  dressed.  For  tight 
cravats  and  neckcloths  are  sure  to  obstruct  the  proper  func- 
tion of  this  organ,  and  bring  on  irritation,  which  may  end  in 
bronchitis  or  consumption. 

479.  — 13.  i Strong  Voice  Demands  Vigorous  Exer- 
cise of  all  the  Body. — We  learn  also  that  they  who  would 
have  the  strongest  and  best  developed  voices  for  speaking  and 
singing  should  pay  special  attention  to  the  general  health,  and 
particularly  to  muscular  exercise  in  the  open  air,  because  the 
voice  depends  so  much  more  upon  the  healthy  condition  of 
the  whole  body  than  it  does  upon  the  healthy  or  unhealthy 
condition  of  the  larynx. 

480.  — 14.  Great  Aid  in  Speaking  can  be  Acquired 
by  Enunciating  the  Simple  Vowel  Sounds.— Experience 
shows  that  great  aid  can  be  given  to  those  who  would  secure 
pure  and  correct  tones  in  speaking  by  slowly  but  distinctly 
enunciating  the  simple  vowel  sounds  of  the  English  language. 
This  not  only  strengthens  the  organs,  but  it  gives  a proper 
training  to  the  laryngeal  muscles,  so  that  in  the  composi- 
tion of  vowels  and  consonants  the  muscles  will  contract  to 
their  proper  amount,  and  only  to  that. 


478.  What  clothing  should  be  given  to  the  neck  ? What  is  one  source  of  bronchitis? 
479.  How  is  the  voice  made  and  kept  clear  and  strong  ? 480.  How  can  poor  speakers 
and  readers  make  themselves  superior  ones  ? 


270 


UITCUCOCK’S  ANATOMY 


COMPARATIVE  PNEUMONOLOGY. 
respiratory  organs. 

481.  Trachea. — The  Trachea  in  some  animals,  such  as  the 
horse  and  cow,  consists  of  complete  rings,  while  in  many  ani- 
mals they  are  only  portions  of  rings,  whose  free  extremities 
are  united  by  membrane.  In  man  these  rings  number  from 
seventeen  to  twenty,  in  the  whale  from  seven  to  twelve,  in 
the  carnivora  from  thirty  to  forty,  and  in  some  camels  one 
hundred  and  ten. 

482.  Bronchi. — The  Bronchial  Tubes  are  usually  two  in 
number,  but  in  the  ruminants,  the  dolphins,  and  some  other 
mammals  there  are  three.  This  third  tube  is  always  the 
smallest,  and  passes  to  the  right  lung. 

483.  Lungs, — In  the  horse  the  lungs  are  undivided,  but 
in  most  quadrupeds  the  number  of  lobes  is  greater  than  in 
man.  In  the  marmot  and  hamster  there  are  five  in  the  right, 
and  three  or  four  in  the  left  lung.  In  the  musk  deer  the 
right  lung  is  nearly  twice  the  size  of  the  left.  The  terminal 
air-cells  of  all  these  animals  correspond  in  size  very  nearly 
wdth  those  of  man.  The  lungs  are  proportionally  the  largest 
in  the  more  powerful  carnivora,  and  smallest  in  the  weak 
herbivora,  and  the  red  blood  corpuscles  are  much  more  abund- 
ant in  the  blood  of  the  former  than  of  the  latter. 

484.  Respiration  of  Birds,  lunglets. — In  Birds  the 
respiratory  apparatus,  like  that  of  Insects,  extends  through  a 
large  part  of  the  body,  (Fig.  264,  p.  271),  not  only  in  the 
lungs  proper,  but  through  the  channeled  bones  which  are  lined 
with  a membrane  for  purifying  the  blood.  (Fig.  265,  p.  271.) 

4S1.  TIow  does  the  Iracliea  in  many  of  tiio  lower  animals  differ  from  that  of  man? 
What  is  the  relative  number  of  ring's  in  each  ? 4S2.  What  is  said  of  the  number  of  the 
jn'incipal  bronchial  tubes?  4S3.  Wliat  of  the.  number  of  lobes  in  many  quadrupeds?  In 
M’hat  animals  are  the  lun"8  lart'est  and  in  what  ones  weakest?  4S4.  How  is  the  respir- 
atory apparatus  of  birds  and  insects  alike? 


Lungs  of  a Bird. 


Fig.  265. 


Pulmonary  Apparatus  of  a Pigeon,  as  seen  on  removing  the  Anterior  Wall  of  the  f 

Thorax,  a.  Trachea.  &.  Bronchi,  c.  Lungs,  cf.  Apertures  of  Communication  '■ 

with  Air-Cells.  [, 

12* 


272 


HITCHCOCK’S  ANATO]^[Y 


Large  air-sacs  are  also  contained  in  the  abdomen,  freely  com- 
municating with  the  lungs,  and  acting  as  reservoirs  for  them. 
A minute  examination  of  the  structure  of  these  organs  shows 


Tig.  266. 


Lunglet  of  a Fowl.  A.  Section  passing  in  the  direction  of  the  Bronchus.  B.  Sec- 
tion cutting  it  across. 


Fig.  26Y. 


Lungs  of  Frog.  a.  Hyoid  Apparatus. 
h.  Cartilaginous  Bing.  c.  Lungs  Proper. 


that  they  are  made  up  of  lo- 
bules or  lunglets,  each  of 
which  has  its  own  system  of 
vessels,  and  but  little  com- 
munication with  the  other 
lunglets. 

485.  lungs  of  Reptiles. 
— The  Hiss  of  Serpents. — 
Mechanism  of  Respira- 
tion.— The  Lungs  of  the 
several  orders  of  Reptiles  are 
for  the  most  part  capacious 
sacs,  the  extent  of  surface  in 
which  is  but  little  increased 
by  smaller  sacs  or  vessels 
within  them.  In  the  Frog, 


What  appendages  do  they  have  which  do  not  exist  in  quadrupeds  ? 4S5.  What  are  the 
lungs  of  reptiles? 


J VD  PHYSIOLOGY. 


273 


Fig.  268, 


Lungs  of  Serpents,  a.  Trachea.  5.  Bronchi,  c.  Right  Lung,  c'.  Left  Lung. 
d.  Pulmonary  Artery. 

for  example,  the  bronchi  terminate  in  capacious  cavities,  upon 
the  sides  of  which  are  the  pulmonary  blood-vessels.  In  many 
serpents  the  pulmonary  apparatus  consists  of  a long  cylindrical 
sac  or  lung  upon  the  right  side  of  the  body,  the  corresponding 
one  on  the  left  side  being  merely  rudimentary,  as  seen  in  Fig. 
268.  Serpents  are  capable  of  expiring  and  inhaling  large 
quantities  of  air,  which  compensates  for  the  want  of  a great 
internal  surface  of  lungs.  And  the  peculiar  hiss  made  by 
them  is  simply  a prolonged  expiration  of  air  from  the  lungs. 


How  is  it  in  frogs  and  serpents?  What  makes  the  hiss  of  serpents  ? 


274 


HITCHCOCK’S  ANATOIMY 


In  aquatic  serpents  the  amount  of  air  contained  in  the  body 
tends  to  make  it  buoyant,  and  at  the  same  time  supplies  the 
wants  of  the  animal  during  a long  immersion.  In  frogs  and 
many  of  the  class  reptilia  the  air  is  forced  into  the  lungs  by 
a process  similar  to  that  of  swallowing.  Taken  as  a whole, 
this  order  is  remarkable  for  the  feebleness  of  its  respiratory 
actions,  and  the  length  of  time  which  the  function  can  be  sus- 
pended without  injury.  The  temperature  in  which  the  ani- 
mal lives,  however,  greatly  modifies  the  amount  of  air  exhaled 
and  inhaled. 

486.  Gills  of  Fishes.  — The  Respiratory  apparatus  of 
Fishes  consists  of  Gills  for  procuring  the  air  contained  in 
Avater.  The  Gills  are  fringes  of  minute  bronchial  tubes  sus- 
pended from  cartilaginous  and  bony  arches,  that  are  situated 


How  do  frogs  inspire?  What  efioct  has  the  temperature  upon  the  respiration  in  this 
class  of  animals  ? 48G.  What  are  the  organs  of  respiration  in  hshes?  Describe  the  gills* 


AND  PHYSIOLOGY. 


275 


just  behind  the  lower  jaw.  ‘'These  are  disposed,  in  most 
fishes,  in  fringed  laminse,  which  are  set  close  together  like 
the  barbs  of  a feather,  and  are  attached  on  each  side  of 
the  throat  in  double  rows,  to  the  convex  margins  of  four  or 
five  long,  bony,  or  cartilaginous  arches,  which  are  suspended 
from  the  hyoidean  arch.'’ 

487.  Air-Bladder. — Another  organ  which  perhaps  claims 
attention  here,  is  the  Air-Bladder.  This  is  a small  shut  sac 
— sometimes  nearly  subdivided  into  two  or  more  sections  by 


Fig.  211, 


Air-Sac  of  Fish  (Carp),  a.  b.  A Divided  Form,  c,  d.  A Tube  connecting  it  with  the 
Esophagus  o. 

a membranous  division — which  lies  near  the  middle  of  the 
back.  In  most  cases  it  has  no  connection  with  any  other  or- 
gan, but  sometimes  has  an  opening  into  the  esophagus  or 
stomach.  The  uses  for  which  it  has  been  supposed  to  exist, 
are  to  enable  the  fish  to  alter  its  specific  gravity,  and  also  to 
aid  in  respiration  in  some  manner.  It  has  also  been  conjec- 
tured that  it  aids  the  sense  of  hearing,  since  it  is  in  direct 
connection  with  the  auditory  apparatus.  It  is  filled  with 
atmospheric  air,  with  greatly  varying  proportions  of  oxygen 
and  nitrogen.  Some  fishes  that  leave  the  water  occasionally 
and  crawl  over  the  land,  have  a cavity  in  the  side  of  the  head 
for  water,  which  is  in  contact  with  a respiratory  apparatus, 
and  thus  the  fish  can  live  for  some  time  out  of  its  native  ele- 
ment.— Wyman. 


48T.  Describe  the  air-bladder.  What  docs  it  sometimea  communicate  with  ? Give  its 
probable  uses.  What  is  it  filled  with  ? 


276 


HITCHCOCK’S  ANATOM 


488.  Trachea  of  Insects. — Spiracles. — Meelianism  of 
Respiration. — Wisdom  of  this  Arrangement. — Tlie  res- 
piratory vessels  of  Insects  are  analogous  to  those  of  birds 
in  that  they  extend  through  a large  part  of  the  body. 

Fia.  272. 


Trachea  of  Water-Scorpion,  a.  Head.  &.  First  Pair  of  Legs.  c.  First  Segment  of 
Thorax,  d.  Second  Pair  of  wings,  e.  Second  Pair  of  Legs.  f.  Tracheal  Trunk,  g.  One 
of  the  Stigmatte.  h,  Air-Sac. 

The  essential  organs  are  Tracheae  or  air-vessels,  which  open 
upon  the  sides  of  the  body,  and  freely  communicate  with  one 
another.  Air  sacs  are  found  in  the  front  parts  of  the  body 

488.  What  arc  the  essential  organs  of  respiration  in  insects  ? Whereabouts  in  the  ani- 
mal are  the  trachcoe  found  f 


AXD  niYSIOLOGY. 


27T 


of  some  insects,  and  the  tracheae  are  very  minute,  ramifying 
through  the  most  delicate  organs  of  the  body,  which  plan 
allows  a rapid  aeration  of  the  blood,  and  greatly  assists  in 
diminishing  the  specific  gravity  of  the  animal.  The  openings 
upon  the  surface  of  the  body  are  called  Spiracles  or  Stigmata, 
and  are  either  oval  or  made  in  the  shape  of  a slit,  as  is 
seen  in  the  adjoining  cut.  In  the  soft-skinned  insects  they 


are  surrounded  by  a ring  of  cartilage,  to  prevent  their  closing 
by  ordinary  accidents  or  pressure,  and  all  spiracles  are  pro- 
tected by  a kind  of  sieve  or  grating,  made  up  of  hairs  ex- 
tending from  either  side  of  the  aperture,  which  keeps  out 
dust,  that  would  otherwise  enter  with  the  air  and  stop  the 
passage.  The  interchange  of  air  is  effected  by  the  enlarge- 
ment and  contraction  of  the  abdomen.  The  rings,  (or  skele- 
ton), which  surround  the  abdomen,  are  seldom  inflexible,  but 
are  made  up  in  one  part  of  membrane,  and  the  horn-like  ends 
are  brought  together  by  muscular  contraction,  by  which 
means  expiration  is  effected.  The  enlargement  or  inspira- 
tion is  accomplished  by  the  simple  elasticity  of  the  encasing 
rings  of  the  body,  as  well  as  of  the  trachea.  Hence,  full- 
ness is  the  natural  or  passive  state  of  the  respiratory  or- 


What  are  the  spiracles  ? How  are  they  soinetinies  protected  ? Give  the  mechanism 
of  respiration. 


278  HITCHCOCK’S  anatomy 

gans,  as  was  seen  to  be  the  case  with  birds.  Still  another 
way  in  which  respiration  is  effected,  is  by  the  sliding  of  one 
ring  inside  the  next  one,  like  the  joints  of  a hand  telescope, 
and  their  return  by  the  elasticity  of  the  tissues  of  the  body. 
And  we  can  not  fail  to  observe  the  beautiful  design  of  the 
Creator,  when,  though  he  furnished  but  a limited  circulation 
of  fluid,  yet  fully  compensated  for  it  by  introducing  the  air  in 
minute  tubes  to  the  very  center  of  every  tissue. 

489.  Crustaceans . — These  animals  breathe  mostly  by  gills. 
The  Myriapods  have  proper  tracheae,  though  with  some  respi- 
ration is  chiefly  cutaneous,  that  is,  directly  through  the  skin. 
The  Arachnoid  or  Spider  tribe  sometimes  have  tracheae  and 
sometimes  even  lungs.  The  gills  of  the  Crustaceans  are  situ- 
ated in  different  parts  of  the  body,  more  especially  on  the 
feet. 

490.  Molluscs. — In  the  Acephala  the  blood  before  return- 
ing to  the  heart  passes  through  a bronchial  organ  or  gill, 
which  opens  and  closes  for  the  ingress  and  egress  of  water. 
Some  of  the  Cephalophora  have  gills ; others  lungs,  and  others 
a system  for  the  circulation  of  water  containing  air,  through 
different  parts  of  the  body.  The  Cephalopoda  all  respire  by 
gills ; but  they  have  also  an  aquiferous  system. 

491.  lladiates. — ^^The  simple  exposure  of  the  surface  of 
a jelly-fish  or  polyp  to  the  action  of  the  fluid  around  it  is 
sufficient  to  carry  on  all  the  changes  which  take  place  in  its 
simple  kind  of  respiration.’’ — Prof.  J.  Wyman.  Nearly  all 
the  Radiates  have  such  an  aquiferous  system.  But  many 
of  them  have  other  organs  for  breathing.  The  Echinoderms 
have  gills ; also  sometimes  their  organs  of  prehension  and 
locomotion  form  a respiratory  apparatus. 


What  instance  of  compenaation  is  shown  here  ? 480.  Do  any  crustaceans  breathe  by 
gills  ? 400.  What  is  the  breathing  apparatus  of  molluscs  ? 491.  What  is  tho  respiratory 
apparatus  of  radiates  ? 


AKD  PHYSIOLOGY. 


279 


THE  SOUNDS  PRODUCED  BY  ANIMALS. 

492.  Among  vertebrates  the  production  of  vocal  sounds  is 
confined  to  the  air-breathing  classes,  since  no  fish  or  gilled 
animal  is  able  to  make  any  sound  by  means  of  the  special 
organs  which  are  provided  for  that  purpose  in  other  animals. 

493.  Laryngeal  Pouches,  or  Sacs, — Nearly  every  mam- 
mal can  make  some  vocal  sound,  and  the  structure  of  the 
larynx  in  all  very  closely  resembles  that  of  man.  The  howl- 
ing apes  present  the  most  striking  difference  in  these  organs. 
They  have  pouches,  or  laryngeal  sacs  as  they  are  called, 
connected  with  the  larynx,  which  increase  the  loudness  of 
the  voice  simply  by  the  resonance  of  the  voice  in  these  cavities. 

494.  The  Two  Larynges  of  Birds — The  Trill  of  Birds. 
— In  birds  the  vocal  organs  are  somewhat  different  from  those 
of  man.  There  is  in  them  a larynx,  called  the  superior 
larynx,  at  the  summit  of  the  trachea,  w*hich  seems  designed 
mainly  for  the  ingress  and  egress  of  air.  But  the  vocal 
sounds  for  which  birds  are  so  remarkable  are  made  by  Avhat 
is  called  the  inferior  larynx,  which  is  situated  at  the  lower 
extremity  of  the  trachea.  This  is  most  complex  in  bird^ 
which  have  the  greatest  powers  of  song.  The  two  or  three 
lower  rings  of  the  trachea  are  usually  consolidated  into  one^ 
and  in  the  interior  a cross  bone  runs  from  front  to  back  which 
has  upon  its  upper  edge  a small  membrane  of  a crescentic- 
shape,  which  is  so  lax  that  it  can  freely  vibrate  when  the  air 
is  made  to  pass  rapidly  over  it.  This  in  its  action,  is  anal- 
ogous to  the  reed  of  the  clarionet  or  melodeon.  It  is  by  the 
vibration  of  this  membrane  that  the  peculiar  trill  of  many 
singing-birds  is  so  beautifully  executed.  The  intensity  of  the 

492.  What  vertebrates  alone  can  make  vocal  sounds?  493.  What  is  said  of  the  struc-r 
ture  of  the  larynx  in  all  mammals  ? What  is  the  peculiarity  among  the  howling  apes  ? 
494.  How  many  larynges  have  birds?  Give  the  function  of  each.  What  peculiarity  in 
the  lower  part  of  the  trachea  ? 


280 


HITCHCOCK’S  ANATOMY 


tune  is  greatly  increased  by  the  construction  of  the  trachcj^ 
and  bronchi.  Birds  whose  voices  have  a very  extensive 
musical  scale  are  able  to  shorten  and  lengthen  their  wind- 
pipe considerably,  and  to  that  end  have  very  thin  wings  and 
large  membranous  interspaces.” 

495.  Larynx  of  Reptiles. — Reptiles  have  an  imperfect 
kind  of  larnyx,  which  is  located  at  the  point  where  the  trachea 
opens  into  the  pharynx.  The  only  sounds  wdiich  they  can 
make  is  the  croak  of  the  frog  and  hiss  of  the  serpent,  turtle, 
or  lizard.  The  common  Fiw  has  two  vesicles  or  little  bao;3 
behind  the  angle  of  the  mouth,  which  arc  much  distended  at 
the  beginning  of  summer  and  at  pairing  time,  which  accounts 
for  their  loud  croaking  at  these  seasons. 

496 . Sounds  Made  by  Insects . — As  we  descend  the  scale 
of  animals,  we  find  in  no  other  a larynx  or  organ  of  voice, 
and  hence  all  the  sounds  made  by  them  are  not  the  sounds 
of  the  voice,  but  simply  noises  which  are  for  the  most  part 
made  by  their  extremities.  The  sounds  made  by  insects  such 
as  approach  most  nearly  to  those  of  vertebrate  animals,  are 
produced  by  vibrations  of  a membranous  plate  situated  just 
over  the  spiracles.  And  in  general  those  insects  that  fly  the 
most  rapidly,  and  whose  wings  move  the  fastest,  make  the 
most  noise,  while  those  which  move  more  slowly  seem  only  to 
fan  the  air  with  their  wings.  Other  sounds  are  produced  by 
mastication.  Thus,  an  army  of  locusts,  when  eating,  makes  a 
sound  which  very  much  resembles  the  noise  of  a crackling  fire. 
A genus  of  ants  make  a sound  by  striking  some  hard  sub- 
stance with  their  mandibles,  or  arm-like  appendages.  A 
species  of  beetle  that  bores  in  old  timber  (called  the  death 
watch)  makes  a sound  in  a similar  way,  and  if  it  be  answered 
by  its  mate  the  signal  will  be  repeated  : but  if  no  answer  be 
given,  the  animal  changes  its  position  before  it  produces  its 
‘Hick”  again.  The  shrill  sound  of  the  grasshopper  and  the 


What  rise  i»  It?  What  construction  increases  the  intensity  of  their  tones?  495.  W^hat 
is  the  larynx  of  reptiles?  What  is  their  voice ? 49G.  Do  insects  have  a larynx?  In 
what  different  ways  arc  sounds  made  hy  insects  ? 


AND  PHYSIOLOGY. 


281 


so-called  locust  is  made  by  rubbing  together  the  anterior  pair 
of  wings,  upon  the  nervures  or  framework  of  the  wings,  on 
which  are  found  file-like  edges.  In  a large  species  of  this 
kind  living  in  Brazil,  which  has  a drum-like  appendage  un- 
der the  wings,  the  sound  can  be  heard  a mile ; and  if  a man 
of  ordinary  stature  possessed  a proportionably  loud  voice,  he 
could  be  heard  all  over  the  world. 

497.  Sounds  of  Moll  use  a. — Among  the  Cephalopods  there 
are  a few  individuals  which  are  able  to  make  a clear,  bell-like 
sound,  but  the  origin  of  it  is  unknown. 

497.  Whali  is  said  of  sounds  made  hy  moUua«s  ? 


ICHOROLOGY,  OR  HISTORY  OF  THE  ORGANS  OF  SECRETION.— 
THE  LYMPHATIC  AND  SECRETORY  SYSTEM. 

DEFINITIONS  AND  DESCRIPTIONS. 


498.  The  Body  is  Constantly  Undergoing  a Change. — 
We  have  seen  that  the  human  body  is  constantly  undergoing 
Fig.  274.  changes  in  its  constituent 

parts.  The  nutrient  por- 
tion of  the  food  designed 
for  the  support  and  growth 
of  the  different  tissues  is 
conveyed  by  the  lacteals  to 
the  left  sub-clavian  vein, 
w^here  it  enters  the  general 
circulation ; while  the  par- 
ticles which  are  constantly 
set  free  in  all  parts  of  the 
body  are,  by  vessels  of  the 
; same  general  character, 
^ called  lymphatics,  con- 
u ^ veyed  to  the  blood  and 
thence  to  the  lungs. 

499.  The  Lacteals  a 
Variety  of  the  lymphat- 
ics. — A more  correct 
however, 

tf,  Superficial  Lymphatic,  less  complex  in  struc-  botll  SCtS  of  absorb- 

luro.  c,  <ty  Lymphatic  laid  open  to  show  the  & 

Valves,  c,  </,  e.  eut  vessels  under  the  class 

of  lymphatics,  making  the  lacteals  only  a variety,  since  their 


A,  rt.  Deep-seated  Lymphatic  Gland.  &,  Lym- 
phatics which  Supply  and  Empty  the  Gland.  B arrangement. 


49S.  How  is  it  that  the  body  is  constantly  undergoing  change ? 499.  What  may  tbs' 
lacteals  bo  properly  called  ? 


AND  PHYSIOLOGY 


283 


Fig.  275. 


The  Lymphatics  of  the  Body. 


II  81: 


HITCHCOCK’S  A N A T O U Y 


cliicf  diiTcrcnce  consists  in  the  kind  of  material  they  convey, 
and  not  in  structure  or  function. 

500.  The  Lymphatics — Their  Similarity  to  Veins  and 
Arteries — Their  Appearance  when  Injected  with  Mercury. 
— The  lymphatics  are  very  delicate,  minute  and  transparent 
vessels  like  the  capillaries,  remarkable  for  their  uniformity  of 


rio.  276. 


A View  of  the  Vessels  and  Lymphatic  Glands  of  the  Axilla.  1,  The  Axillary  Artery. 
2,  Tlie  Axillary  Vein.  3,  The  Brachial  Artery.  4,  The  Brachial  Vein.  5,  The  Primi- 
tive Car(»tid  Artery.  6,  The  Internal  Jnfcular  Vein.  7,  The  Sub-Ciitaneous  Lymphat- 
ics of  the  Arm  at  its  Upper  Part.  8,  Two  or  three  of  the  most  Inferior  and  Superficial 
Glands  into  which  tlie  Superficial  Lymphatics  empty.  9,  Tlie  Deep-seated  Lymphatics 
which  accompany  the  Braciiial  Artery.  10,  The  Lymphatics  and  Glands  which  accom- 
pany the  Infra-Scapular  Blood-Vessels.  11,  The  Glands  and  Lymphatics  accompanying 
the  Thoracica  Longa  Artery.  12,  Deeper-seated  Lymphatics.  13,  The  Axillary  Chain 
of  Glands.  14,  The  Acromial  Branches  of  the  Lymphatics.  15,  The  Jugular  Lymphatics 
and  Glands  10.  17,  The  Lym|)liatic,8  which  empty  into  the  Sub-Clavian  Vein  near  its 
Junction  with  the  liiglit  Internal  Jugular  Vein. 


AND  PHYSIOLOGY 


285 


Tig.  2n. 


size,  of  a knotted  appearance,  and  very  frequently  dividing  into 
two  nearly  equal  branches.  Like  veins  and  arteries,  they  have 
three  coats,  with  folds  of  the 
inner  coat  for  the  formation 
of  valves,  giving  them  a knot- 
ted appearance.  They  com- 
mence in  a minute  net-work 
in  nearly  every  organ  of  the 
body,  and  soon  unite  into  a 
few  large  trunks  which  take 
a direction  towards  the  veins 
in  the  lower  part  of  the  neck. 

This  net-work  is  so  exceed- 
ingly delicate,  that  when  filled 
with  mercury  it  presents  the 
appearance  of  a sheet  of  silver. 

The  necessity  of  such  an  im- 
mense number  of  these  vessels 
arises  from  the  constant  lib- 
eration of  the  waste  particles 
of  matter  which  need  to  be 
removed  as  soon  as  possible, 
that  the  deposition  of  new 
particles  may  not  be  prevented. 

501.  Lymphatic  Glands. — 

As  the  minute  lymphatics 

unite  into  larger  trunks,  they  ^ Lymphatic  The- 

racic  Duct.  1,  Arch  of  the  Aorta.  2, 
Thoracic  Aorta.  8,  Abdominal  Aorta.  4,  Arteria  Innominata.  5,  Left  Carotid.  6, 
Left  Sub-CIavian.  7,  Superior  Cava.  8,  The  two  Venae  Innominatae.  9,  The  Internal 
Jugular  and  Sub-Clavian  Vein  at  each  side.  10,  The  Vena  Azygos.  11,  The  Termination 
of  the  Vena  Hemi-Azygos  in  the  Vena  Azygos.  12,  The  Keceptaculum  Chyli : several 
Lymphatic  Trunks  are  seen  opening  into  it.  13,  The  Thoracic  Duct  dividing,  opposite 
the  Middle  Dorsal  Vertebra,  into  two  branches,  which  soon  re-unite  ; the  course  of  the 
Duct  behind  the  Arch  of  the  Aorta  and  Left  Sub-Clavian  Artery  is  shown  by  a dotted 
Line.  14,  The  Duct  making  its  turn  at  the  Koot  of  the  Neck  and  receiving  several  Lym- 
phatic Trunks  previous  to  terminating  in  the  Posterior  Angle  of  the  .Junction  of  the  In- 
ternal Jugular  and  Sub-Clavian  Veins.  15,  The  Termination  of  the  Trunk  of  the  Lym- 
phatics of  the  Upper  Extremity. 


500.  Describe  the  lymphatics.  How  many  coats  have  they?  What  is  said  of  the  net- 
work which  they  make  ? Why  the  necessity  of  such  a multitude  ? 


286 


n I T c n c o c K ’ s a x a t o y 


pass  throngli  small  bodies,  varying  in  size  from  a mustnrd-sced 
to  a pea,  which  are  called  lymphatic  glands,  whose  design  is 
not  yet  clearly  understood.  They  then  pass  upwards  towards 
the  heart  as  already  mentioned,  those  of  the  left  side  of  the  body 
emptying  themselves  through  the  thoracic  duct,  while  those  of 
the  right  side  enter  a tube  running  parallel  to  this,  called  the 
Iirht  Lymphatic  Duct,  15,  Fig.  277. 


Fia.  278. 


A Front  View  of  the  Femoral,  Iliac,  and  Aortic  Lymphatic  Vessels  and  Glands.  1,  Sa- 
phena Ma^^na  Vein.  2,  External  Iliac  Artery  and  Vein.  8,  Primitive  Iliac  Artery  and 
Vein.  4,  The  Aorta.  5,  Ascending  Vena  Cava.  6,  7,  Lymphatics  which  are  alongside 
of  the  Saphena  Vein  on  the  Thigh.  8,  Lower  Set  of  Inguinal  Lymphatic  Glands  which 
receive  these  Vessels.  0,  Superior  Set  of  Inguinal  Lymphatic  Glands  which  receive  these 
Vesstds.  10,  The  Chain  of  Lymphatics  in  Front  of  the  External  Iliac  Vessels.  11,  Lym- 
phatics which  accompany  the  Circumflex  Iliac  Vessels.  12,  Lumbar  and  Aortic  Lym- 
phatics. 13,  AfTcrent  Trunks  of  the  Lumbar  Glands,  forming  the  Origin  of  the  Thoracic 
I)uct.  14,  Thoracic  Duct  at  its  coinincnccmcnt. 


601.  Doscribo  the  lymphatic  glands.  What  is  the  right  lymphatic  duct? 


AND  PHYSIOLOGY. 


287 


502.  Material  Absorbed 
Various  Substances  Ap- 
plied to  the  Skin— Nutri- 
ment Sometimes  Intro- 
duced through  the  Skin — 
Thirst  Quenched  by  Wet 
Clothes. — These  vessels  not 
only  remove  useless  particles, 
but  absorb  substances  applied 
to  the  skin,  although  some 
maintain  that  this  is  done  by 
the  veins  alone.  And  this  is 
sometimes  an  effective  method 
of  administering  medicines 
which  it  is  not  expedient  to 
introduce  through  the  mouth 
and  nostrils,  thus  producing 
a desired  effect  upon  the  cir- 
culatory and  venous  systems 
without  offending,  or  in  any 
manner  affecting  the  senses  or 
feelings  of  the  person  taking 
the  medicine.  For  instance, 
spirits  of  turpentine  rubbed 
upon  the  hands  of  many  per- 
sons, and  green  leaves  of  to- 
bacco placed  upon  the  ab- 
domen, will  often  produce 


by  Lymphatics  — Effect  of 


Fig.  2 '79. 


A Front  View  of  tlie  Deep-seated  Lym- 
phatics of  the  Thigh.  1,  Lower  End  of  the  Aorta.  2,  Primitive  Iliac  Vein.  3,  4,  Ex- 
ternal Iliac  Artery  and  Vein.  5,  Femoral  Artery.  6,  Section  of  the  Femoral  Vein.  7, 
Vena  Saphena  on  the  Leg.  8,  Lymphatics  near  the  Knee.  9,  Lymphatics  accompany- 
ing the  Femoral  Vessels.  10,  Deep  Lymphatics  going  from  the  inside  of  the  Thigh  to 
the  Glands  in  the  Groin.  11,  Lymphatics  of  the  External  Circumflex  Vessels.  12,  Lym- 
phatics on  the  outer  side  of  the  Femoral  Vessels.  13,  A Lymphatic  Gland  always  found 
outside  of  the  Vessels.  14,  A collection  of  Vessels  and  Glands  from  the  Internal  Iliac 
Vessels.  15,  The  Lymphatics  of  the  Primitive  Iliac  Vessels. 


502.  What  do  the  lymphatics  absorb  ? What  value  of  this  fact  at  times  ? Give  a com- 
mon effect  of  tobacco  and  turpentine  rubbed  upon  the  skin. 

13 

I 

i 


♦288  HITCHCOCK’S  anatomy 

distressing  sickness.  Mercury,  too,  rubbed  vigorously  upon 
iilmost  any  part  of  the  skin,  will  in  a short  time  produce  sali- 
vation, because  the  minute  globules  of  this  metal  arc  forced 
through  the  pores  of  the  skin,  and  arc  absorbed  by  the  lym- 
phatics. In  some  cases  where  disease  has  so  affected  the 
mouth  or  passage  to  the  stomach  as  to  prevent  the  intro- 
duction of  food,  life  has  been  maintained  for  a considerable 
time  by  nutriment  introduced  through  the  skin,  by  means  of 
a bath  of  warm  milk.  Shipwrecked  sailors  in  an  open  boat 
and  deprived  of  fresh  water,  can  for  some  time  partly  assuage 
their  thirst  by  wetting  their  clothes  with  salt  water,  or  better 
still,  by  a thorough  wetting  during  a rain  storm. 

503.  Poisons  Introduced  tliroiigli  tlie  Skin  by  the  Lym- 
phatics.— The  poisoning  which  frequently  occurs  from  the 
contact  of  the  skin  with  sumach  or  ivy,  is  owing  to  the  ab- 
sorption of  poisonous  influence  by  these  vessels.  Animal  poi- 
sons, too,  such  as  the  venom  of  mad  dogs,  serpents,  and  in- 
sects, are  introduced  to  the  general  system  by  the  lymphatics. 

504.  Pressure  Increases  their  Action. — Pressure  greatly 
increases  the  action  of  the  lymphatic  vessels.  This  is  seen 
in  a broken  limb  which  has  been  tightly  bandaged,  when  the 
muscles  become  very  small  from  the  removal  of  the  tissue  by 
the  excessive  action  of  the  lymphatics. 

505.  Venous  Absorption — Pvadicles. — Besides  lymphat- 
ics, the  small  veins  perform  the  function  of  absorption.  It  is 
easily  seen  that  these  can  perform  the  same  office  as  the  lym- 
phatics, since  both  of  them  carry  their  fluids  to  the  heart  for 
purifleation,  and  no  other  use  is  made  of  them  on  their  way 
thither.  These  radicles,  or  small  veins,  perform  a very  im- 
portant function  in  the  stomach  by  the  rapid  absorption  of  the 
watery  portion  of  all  liquids,  and  its  conveyance  to  the  gen- 

Th  nutvinu*nt  ovor  conveyed  into  the  system  in  this  way  ? Can  thirst  be  quenched  in  i 
tliis  way  ? 51^5.  Do  tlii<  lymphatics  ever  introduce  poison  into  the  system?  504.  How 
docs  pressure?  affect  the  nclion  of  lymi)liatics  ? What  example  of  it?  505.  What  is  said 
of  ubsori)llon  by  the  veins?  What  important  service  do  the  radicles  perform  in  the 
stomach  ? 


AND  PHYSIOLOGY. 


289 


eral  circulation  without  passing  through  the  circuitous  course 
taken  by  the  food. 

506.  Effect  of  Bloisture  upon  tlie  Lymphatics —Moist- 
ure stimulates  these  absorbent  vessels  to  a morbidly  vigorous 
action.  Hence  a person  surrounded  by  a moist  atmosphere 
or  immersed  in  water  itself,  will  acquire  additional  weight. 
And  as  an  excessive  use  of  the  eliminating  organs  of  the  sys- 
tem is  injurious,  locations  for  houses  should  be  selected  as  far 
as  possible  on  dry  places,  and  not  on  wet  or  low  land  where 
heavy  fresh  water  fogs  prevail.  For  the  same  reason  damp 
clothing  injures  the  body,  because  it  unduly  stimulates  the 
lymphatics. 

507.  Amount  of  Matter  taken  up  by  the  Absorbents. — 
The  amount  of  Chyle  and  Lymph  poured  into  the  blood  by 
the  lymphatics  and  radicles  is  about  one  third  of  the  whole 
amount  in  the  body. 


ORGANS  OF  SECRETION. 

508.  Follicles  and  Glands.— Character  of  Secretions.— 
Size  of  Follicles. — ^The  organs  which  perform  the  office  of 
secretion  in  the  body  are  Follicles  and  Glands.  The  former 
of  these  are  small  bodies  in  the  form  of  sacs  or  tubes,  exist- 
ing for  the  most  part  in  the  skin  and  mucous  membrane,  one 
end  of  which  opens  upon  the  surface  of  the  membrane,  for  the 
discharge  of  its  secretion.  The  secretion  poured  from  these 
varies  in  consistency  from  the  thick  wax  of  the  ear,  to  the 
limpid  juice  of  the  stomach.  The  follicles  vary  also  in  size 
from  tubes  perceptible  to  the  naked  eye  down  to  those  th  of 
an  inch  in  diameter. 

509.  Glands, — The  Glands  are  soft  solids  of  various  sizes 
(the  liver  the  largest)  made  up  of  lobules  or  small  bodies  of 

506.  How  does  moisture  affect  the  lymphatic  action  ? How  do  damp  clothes  injure  the 
wearer?  507.  What  is  the  amount  of  matter  taken  up  by  the  absorbents?  508.  What 
is  tlie  anatomy  of  the  follicles?  Of  what  character  is  their  secretion?  What  is  their 
size  ? 500.  What  is  a gland  ? 


290 


HITCHCOCK’S  ANATOMY 


rio.  280. 


Intimate  Structure  of  a Gland  (the  Parotid), 


minute  proportions,  each  of  which  has  an  artery,  a vein,  and 
a duct  to  carry  away  the  secretion.  These  ducts  unite  with 
one  another,  until  they  form  one  tube  called  the  principal 
outlet  of  the  organ.  In  some  glands  these  lobules  are  quite 


Fig.  281. 


Lymphatic  Vessels.  Mesentery. 

Cliyliferous  Vessels. 


ANATOMY  AND  PHYSIOLOGY. 


291 


large — one  fourth  of  an  inch  in  diameter — while  frequently 
they  are  nearly  the  size  of  a mustard  seed.  The  color  is  also 
various.  That  of  the  liver  is  a dark  red,  the  pancreas  of  a 
pale  white  or  gray,  the  little  gland  in  the  inner  angle  of  the 
eye  pink,  and  the  kidneys  a reddish  yellow. 

510.  Function  of  Secretion. — The  function  performed  by 
these  vessels  is  an  exceedingly  curious,  and  not  easily  ex- 
plained phenomenon.  For  from  the  blood  are  eliminated  by 
the  various  secretory  organs,  bile,  saliva,  perspiration,  tears, 
etc.,  none  of  which  exist  there  as  such,  but  they  seem  to  be 
formed  from  the  chemical  elements  in  the  blood  by  the  glands 
themselves. 

511.  Effect  of  the  Emotions  upon  the  Secretions. — 
The  mental  emotions  greatly  affect  the  secretions.  A person 
in  fear  is  often  covered  with  a cold  perspiration,  and  in  some 
persons  in  the  same  situation  the  salivary  glands  cease  to  act. 
On  the  other  hand  the  thought  of  savory  food  has  been  known 
to  cause  the  saliva  to  issue  in  a jet  from  the  sides  of  the 
mouth. 

512.  Reserve  Glands. — Some  glands  also  act  only  on  parti- 
cular occasions,  as  in  the  case  of  a broken  bone,  or  cut  in  the 
flesh,  when  the  appropriate  vessels  set  themselves  at  work  to 
repair  the  injury. 

513.  Secretion  after  Death. — Certain  secretions  arc  con- 
tinued for  a time  after  the  death  of  the  individual.  Thus  it 
has  been  observed  that  the  hair  and  nails  grow  considerably 
after  death,  provided  the  disease  was  a rapid  one,  so  that  the 
system  was  not  reduced  by  loss  or  degeneracy  of  the  blood 
and  nervous  system.  It  is  also  related  that  in  dissecting  the 
poison  apparatus  of  a rattle-snake,  the  poison  was  secreted  so 


Give  the  minute  anatomy  of  the  glands.  Describe  their  ducts.  Mention  their  various 
colors.  510.  What  is  the  use  of  the  glands?  Do  the  secretions  exist  ready  formed  in  the 
blood?  511.  What  is  the  effect  of  the  feelings  upon  secretion?  Give  an  example.  .512. 
What  is  said  of  reserve  glands?  513.  What  is  said  of  secretions  continuing  some  time 
after  death  ? Give  an  example. 


292 


HITCHCOCK’S  ANATOIMY 


fast  that  it  was  necessary  to  dry  it  off  occasionally  during  the 
dissection. 

514.  Vicarious  Secretion. — Anotlier  curious  phenomenon 
connected  with  this  subject  is  vicarious  secretion,  where  one 
organ  performs  the  whole  or  part  of  the  office  of  another. 
This  is  often  seen  in  the  function  of  the  lungs  and  liver,  where 
one  imperfectly  performing  its  office,  is  aided  by  the  other. 
This  vicarious  secretion  is  still  more  apparent  between  the 
liver  and  skin.  For  in  the  disease  known  as  Jaundice,  where 
some  obstruction  is  offered  to  the  passage  or  secretion  of  the 
bile,  it  is  poured  out  by  the  skin,  coloring  it  deeply  yellow, 
and  in  some  instances  it  has  been  known  to  stain  the  linen, 
which  is  worn  next  the  skin,  perceptibly  yellow. 

515.  Ductless  Glands. — In  connection  with  this  subject 
it  is  proper  to  mention  a class  of  organs  known  as  Ductless 
Glands,  or  bodies  which  have  the  form  and  general  structure 
of  glands,  but  no  duct  or  outlet,  and  form  no  secretion,  as  do 
the  true  glands.  These  are  the  Spleen,  the  Thymus  and 
Thyroid  Glands,  and  the  Supra  Renal  Bodies.  Of  these  only 
the  former  will  be  described  here,  since  the  latter  are  most 
perfectly  developed  during  the  earliest,  or  fetal  stage  of  exist- 
ence. 

516.  The  Spleen, — The  Spleen  measures  in  different  indi- 
viduals from  four  to  six  inches  in  its  longest  diameter,  and  is 
situated  under  the  left  extremity  of  the  stomach.  (Fig.  282, 
p.  293.)  It  is  of  a reddish  blue  color,  convex  on  its  external, 
and  concave  on  its  internal  surface.  It  is  very  abundantly 
supplied  with  blood-vessels,  and  consequently  vascular  or 
spongy  in  its  structure.  (Fig.  283,  p.  293.)  Upon  a close 
inspection  it  is  found  to  be  made  up  of  corpuscles  from  one 
third  to  one  sixth  of  a lino  in  diameter,  each  of  which  is  com- 
posed of  nucleated  cells  about  5 oVoth  of  an  inch  in  diam- 
eter. (Fig.  284,  p.  293.) 


rjM.  Stdto  tlio  j)rincIi)lo  of  vloivrions  secretion.  What  remarkable  facts  in  this  connec- 
tion uboiit  jaundice?  .515.  Describe  the  ductless  glands.  What  are  their  names  ? At 
what  period  of  life  are  they  the  most  fully  developed  ? 516.  Describe  the  spleen. 


AND  PHYSIOLOGY. 


293 


Fig.  282. 


Fig.  283. 


Shows  the  Internal  Face  of  the  Spleen  Section  of  the  Spleen, 

where  it  touches  the  Stomach.  1,  Supe- 
rior Extremity.  2,  Inferior  Extremity.  8,  Posterior  Part  of  the  Concave  Face.  4,  An- 
terior Part  of  the  same.  5,  Fissure  of  the  Spleen.  G,  Splenic  Artery.  7,  Splenic  Vein. 
8,  8,  Anterior  Edge  of  the  Spleen.  9,  9,  Its  Posterior  Edge. 


Fig.  284. 


Section  of  the  Spleen  magnified. 


294 


HITCHCOCK’S  ANATOSIY 


517.  Fuiiction  of  tliis  Organ. — Produces  and  Destroys 
the  Red  Blood  Corpuscles. — As  already  stated  there  is  no 
duct  or  outlet  to  this  organ,  or  evidence  of  any  secretion  out- 


Fig.  285. 


Small  Portion  of  the  Spleen  very  highly  magnified,  showing  two  corpuscles  and  the 
minute  Blood-Vessels. 


ward.  But  the  idea  has  occurred  to  physiologists,  though 
with  no  positive  proof  as  yet,  that  a kind  of  secretion  is  pro- 
duced by  the  spleen  which  is  poured  directly  into  the  blood, 
and  consequently  there  is  no  necessity  for  any  outlet.  And 
again  experiments  Iiave  been  carried  so  far  as  to  give  plausi- 
bility to  the  idea,  that  this  organ  is  designed  to  i^oduce 
Mood  corjmsc^cs,  and  at  the  same  time  use  up  those  that  are 

.M7.  or  what  U.SO  Is  tho  s])lccn  ? What  is  said  of  it  as  an  organ  for  producing  blood 
corpMBclcs  ? 


AND  PHYSIOLOGY. 


295 


no  longer  of  service  to  the  body.  Certain  it  is  that  no  other 
organ  in  the  body  has  as  yet  been  discovered  which  subserves 
this  purpose,  and  equally  certain  that  in  cases,  where  large 
wounds  are  to  be  healed,  and  in  certain  other  conditions  of 
the  body,  the  white  corpuscles  are  greatly  increased  in  num- 
ber. 


518.  The  Skin. — Among  those  organs  wdiose  offices  are 
those  of  absorption  and  secretion,  the  Skin  finds  a prominent 
place. 

519.  Made  up  of  Three  Membranes. — This  is  a membrane 
simple  in  its  general  aspect,  but  under  the  microscope  it  is 
found  to  be  composed  of  no  less  than  three  distinct  layers : 
the  Epidermis,  Basement  Membrane,  and  Corium.  It  covers 
every  part  of  the  body,  except  the  portion  immediately  sur- 
rounding the  various  orifices,  and  those  portions  of  the  ex- 
tremities covered  by  the  nails.  It  is  highly  elastic,  as  may 
be  seen  by  the  gaping  of  a long  gash,  and  possesses  a certain 
amount  of  contractility,  owing  to  some  muscular  fibers  con- 
tained in  it. 


520.  Papillae;  their  Size. — Upon  several  portions  of  the 
body  the  skin  is  roughened  by  small  protuberances,  either 
arranged  in  a circular  form,  or  in  rows,  which  are  supplied 


with  one  or  more  loops  of 
nerves.  These  are  termed 
Papillae,  and  are  found  most 
abundantly  in  the  extremi- 
ties, and  especially  upon  the 
palms  of  the  hand  and  soles 
of  the  foot.  They  vary  in 
height  from  to  of  a 
line,  being  of  different  lengths 
in  different  parts  of  the  body. 


Fig.  286. 


PapillfB  from  Palm  of  the  Hand,  magni- 
fied thirty-five  times. 


519.  Of  what  three  membranes  is  the  skin  made  up?  State  their  general  proper- 
ties. 520.  What  are  the  papillae  ? Where  are  they  found  in  the  greatest  numbers  ? 
State  their  size. 


18* 


29G 


HITCHCOCK’S  ANATOMY 


521.  Epidermis  or  Cuticle;  Has  no  Yilalily.—Pij^ment 
Cells. — Composition  of  Pigment-Cells. — The  outer  layer  of 
the  skin  is  called  the  Cuticle  or  Epidermis,  and  bears  the 
same  relation  to  the  true  skin,  that  the  outer  bark  of  the  tree 
does  to  the  inner.  In  thickness  it  varies  considerably  in  the 
different  parts  of  the  body.  It  is  tto  oth  of  an  inch  thick  on 
the  chin,  cheeks  and  brows,  and  th  to  -Jth  of  an  inch  thick 
on  the  soles  of  the  foot.  It  is  merely  a layer  of  albumen — 


PiG.  287. 


Fig.  288. 


Vertical  Section  of  Epidermis  from  a 
Negro,  a,  Deep  Cells  loaded  -with  Pig- 
ment. 5,  Cells  more  elevated  and  some- 
what flattened,  c,  Scaly  Cells  at  the  Sur- 
face. 


Highly  magnified  Pigment-Cells.  A, 
Scales  of  the  Epidermis  filled  with  Pig- 
ment Cells  which  are  seen  separate  at  h. 
B.  Pigment  Cells  from  the  Choroid  Coat 
of  the  Eye. 


the  same  substance  as  the  white  of  an  egg — and  is  secreted 
by  the  true  skin,  in  the  form  of  scales,  which  are  closely 
compacted  together,  and  it  is  in  this  form  that  they  are  de- 
tached from  the  body  by  washing  and  friction.  In  some 
cases,  however,  it  is  detached  in  large  patches,  so  that  after 
certain  skin  diseases  have  run  their  career,  the  whole  epider- 
mis of  the  hand  with  the  nails  adherent  may  be  removed  in 
the  manner  of  a glove.  The  epidermis  contains  no  blood- 
vessels or  nerves,  and  consequently  no  vitality,  it  being  merely 
a secretion  which  hardens  into  a semi-transparent  membrane. 
A part  of  the  cells  of  the  true  skin,  however,  instead  of  se- 
creting the  epidermis,  produce  what  are  termed  the  Pigment 


521.  Dcscrilx*.  the  epidermis.  To  what  does  it  correspond  in  the  tree  ? State  its  thick- 
ness and  chemical  composition.  What  vessels  and  what  colls  docs  it  contain?  Wher® 
are  the  pigment  cells  shown  ? 


AND  PHYSIOLOGY. 


297 


Cells,  which  give  color  to  the  skin.  These  cells  are  best  ex- 
hibited in  the  eye  where  the  pigmentum  nigrum  (black  paint) 
is  secreted,  and  are  of  the  same  kind  with  those  in  the  epi- 
dermis. They  are  oval  or  rounded  granules,  measuring 
20000th  of  an  inch  in  diameter,  and  one  quarter  of  this  in 
thickness,  sometimes  presenting  a polygonal  or  stellate  form. 
They  have  nearly  the  same  composition  as  the  coloring  matter 
of  the  cuttle-fish,  which  contains  a much  larger  proportion  of 
carbon  than  is  contained  in  most  organic  substances,  namely 
58 i parts  in  hundred.  The  development  of  these  cells  de- 
pends mainly  upon  exposure  to  the  sun’s  light.  Hence  we 
see  that  persons  with  a fair  skin  become  of  a darker  hue,  if 
exposed  to  the  strong  and  direct  light  of  the  sun. 


Fig.  289, 


522.  The  Nails;  Mode  of  Growth;  Rate  of  Growth. — 
The  Nails  are  composed  of  the  same  material  as  the  epidermis, 
being  merely  an  altered  form  of  it.  When  their  newest  por- 
tions are  examined  ivith  the  microscope,  they  are  found  to  be 
nucleated  cells  closely  resembling  those  of  the  epidermis, 
Epithelium  cells.  The 
nail  increases  in  length 
by  successive  additions 
to  its  root,  which  push 
it  forward  over  the  end 
of  the  finger,  while  at 
same  time  it  receives 
additional  layers  from 
the  skin  beneath.  The 
nails  of  the  hands  grow 
about  two  fifths  of  a 
line  per  week,  while 
those  of  the  foot  re- 
quire four  times  that  period  for  the  same  amount  of  growth. 
The  blood-vessels  of  the  nails  are  very  abundant,  and  are 


Section  of  the  Tluiinb.  a.  Last  Bone  of  the 
Thumb,  h.  Epidermis  reflected  on  the  Nail.  c. 
Nail.  d.  Epidermis  at  the  Point  of  the  Tumb. 


What  is  very  remarkable  about  the  chemical  composition  of  this  pigment?  What 
does  the  development  of  these  cells  depend  on?  522.  Of  what  composition  are  the  nails? 
Of  what  kind  of  cells  are  they  ? How  fast  do  the  nails  of  the  hand  grow? 


298 


HITCHCOCK’S  ANATOMY 


situated  just  within  the  corium,  into  wliich  tlic  nail  barely 
dips.  And  so  numerous  are  these,  and  of  so  low  a degree  of 
vitality,  that  frequently  the  nails  grow  for  a short  distance 
after  death.  When  the  nails  are  badly  injured,  they  are  sel- 
dom perfectly  regenerated,  because  of  the  injury  done  to  the 
vessels  and  laminae.  A rudimentary  nail  sometimes  is  found 
on  the  second  joint,  when  the  first  is  destroyed.  Cases  are 
also  on  record,  where  the  nails  have  been  shed  and  renewed 
periodically.  The  nails  are  thickest  at  their  most  convex 
portion,  instead  of  their  edges,  and  increase  in  thickness  from 
the  base  to  their  free  edge.  They  grow  only  so  long  as  they 
are  cut,  and  among  the  literary  class  of  the  Chinese,  who 
never  cut  their  nails,  they  are  said  to  attain  only  a length  of 
two  inches.  The  time  necessary  for  a nail  to  grow  its  whole 
length,  varies  from  twelve  to  twenty  weeks. 

522  a.  Basement  Membrane  of  the  Skin. — The  middle 
layer  of  the  skin  is  simply  a basement  membrane,  and  is  in 
fact  the  mucous  layer  of  the  epidermis.  It  is,  however,  of 
little  importance  in  the  functions  of  the  skin,  and  is  believed 
to  be  a separate  layer  merely  because,  when  it  is  immersed  in 
a solution  of  potash  in  connection  with  the  epidermis,  the 
latter  is  dissolved,  while  the  former  is  unchanged. 

523.  The  Corium;  its  Composition;  Nerves  of  the 
Corium. — The  Corium  or  internal  layer  is  the  true  skin, 
since  it  possesses  the  vitality  and  sensibility  of  this  membrane, 
and  contains  all  its  vessels.  It  is  made  up  of  white  and  yel- 
low fibrous  tissue,  the  white  predominating,  except  in  those 
parts  where  occasional  extension  is  required,  where  the  yellow 
exists  in  larger  proportion.  The  blood-vessels  of  the  corium 
are  very  abundant,  terminating  in  the  minute  tubes  which 
supply  tlic  sudoriparous  and  sebaceous  glands  : the  proof  of 
the  abundance  of  which  we  have  in  puncturing  any  part  of 

Why  do  tlio  nails  soinetiinos  prow  after  dcatli?  Why  do  the  nails  seldom  crow  nat- 
urally after  an  injury?  At  what  portion  are  the  nails  the  thickest  ? 522  a.  AVhat  is  tho 
inldillo  layer  of  tho  skin  ? 52:k  Of  what  is  the  corium  composed?  What  is  said  of  the 

ubundaiico  of  blood-vessels  in  the  corium? 


AND  PHYSIOLOGY. 


299 


the  skin  \vith  the  finest  needle,  when  a drop  of  blood  is  sure 
to  follow.  The  nerves  of  sensation  too  are  very  abundant,  as 
Ave  know  by  the  insertion  of  a pin  into  any  part  of  the  body, 
Avhich  invariably  pains  us,  because  w'e  have  wounded  a nerve, 
and  not  an  expanded  surfiice,  like  a membrane. 

524.  Sebaceous  or  Oil  Glands. — The  Sebaceous  Glands 
are  small  elongated  sacs  which  are  generally  gathered  in 
clusters  about  each  of  the 
hairs  of  the  body,  varying 
in  number  from  four  to  twen- 
ty. They  pour  their  secre- 
tion into  the  hair-canals  near 
their  orifices,  and  are  most 
abundant  in  the  parts  of  the 
body  most  exposed,  as  in  the 
skin  of  the  nose.  Their  se- 
cretion in  most  places  resem- 
bles fat,  although  in  the  pas- 
sage of  the  external  ear  a 
substance  resembling  wax 
(cerumen)  is  poured  out. 

524«.  Parasite  in  the 
Sebaceous  Glands. — It  is  a 
fact  curious,  if  not  at  first 
sight  revolting,  that  there  is 
very  constantly  found  in  the 
outlets  to  many  of  the  sebaceous  glands  a parasitic  animal,  as 
represented  by  the  cut.  (Fig.  291,  p.  300.)  'The  occurrence 
of  this  animal  in  almost  every  individual  has  led  one  anat- 
omist to  call  it  a ‘^denizen”  of  the  human  body. 

525.  Sweat  Glands.— length  of  Sweat  Tube  in  the 
Human  Body. — The  Sudoriparous  or  Sweat  Glands  essen- 

What  of  the  nerves  in  the  corium  ? 524.  What  are  the  sebaceous  glands?  Where  are 
tliey  the  most  abundant  ? What  is  their  secretion  ? 524  a.  What  is  said  of  the  parasite 
in  the  skin? 


Fig.  290. 


A View  of  the  Cerumen  Gland 
formed  by  the  Contorted  Tubes.  1, 1^ 
The  Tubes.  2,  The  Excretory  Duct. 
3,  The  Vessels  supplying  it. 


300 


HITCHCOCK’S  A X A T O :sr  Y 


Fm.  291. 


Parasites  of  the  Sebaceous  Glands,  a.  Two  seen  in  their  ordinary  position  at  the 
Orifice  of  the  Gland,  h.  Short  Variety,  c.  Long  Variety. 

tially  consist  of  long  tubes  convoluted  and  twisted  upon  them- 
selves, (Fig.  293,  p.  301),  located  just  beneath  the  corium, 
several  of  which  join  to  form  an  outlet,  which  passes  through 
the  epidermis  in  a spiral  manner,  so  that  as  it  opens  exter- 
nally, a valve  is  made  preventing  the  entrance  of  substances 
from  without,  but  allowing  a ready  exit  to  all  substances  to  be 
discharged  externally.  The  size  of  the  gland  proper  is  about 
y^th  of  an  inch  in  diameter,  and  that  of  the  tube  is  about  4 
inch.  The  outlets  of  these  tubes  (Fig.  292,  p.  301,)  are  called 
the  pores  of  the  skin,  and  are  somewhat  larger  than  the  diam- 
eter of  the  tubes.  The  most  remarkable  fact,  however,  con- 
nected with  these  glands,  is  their  immense  number  in  the  sys- 
tem. Each  tube  when  straightened  measures  on  an  average  one 
fourth  of  an  inch  in  length,  and  by  actual  count  there  are  at 
least  2,800  in  every  square  inch  of  the  body.  (Fig.  293, 
p.  301.)  Now  the  number  of  square  inches  in  a man  of  or- 
dinary height  is  2,500,  wliich  would  make  the  number  of 
pores  or  openings  aliout  7,000,000,  or  the  whole  length  of 


b2.5.  Wh.'ii  i.s  tljo  general  outline  of  the  sweat  glands?  What  is  their  size?  IIow  many 
on  every  B(iuaro  inch  of  the  body  ? What  is  their  aggregate  length  ? 


301 


AND  PHYSIOLOGY. 


Fig.  292. 


Fig.  293. 


Skin  of  the  Palm  showing  Ridges,  Fur- 
rows, Cross  Groves,  and  Pores,  or  Orifices 
of  Sweat  Ducts. 

tube  145,853  feet,  or  48,611 
yards,  or  nearly  28  miles. 

Dalton  says,  153,000  inches 
or  two  and  a half  miles. 

526.  The  Perspiration. 

— Sensible  and  Insensible 
Perspiration. — The  secre- 
tion poured  out  by  these 
glands,  is  a transparent  liquid 
of  an  acid  reaction,  and  of  a 
saltish  taste,  commonly  known 
as  sweat  or  perspiration.  This 
is  produced  in  two  forms, 
known  as  sensible  and  insen- 
sible perspiration,  which  is 
escaping  from  the  body  in 
one  of  these  forms  constantly  during  health,  the  sensible  being 
given  off  whenever  excretion  is  so  great  as  to  leave  moisture 
upon  the  skin. 


Vertical  Section  of  the  Sole  of  the  Foot. 
a.  Epidermis.  &.  Papillary  Structure. 
0.  Cutis,  d.  Sweat  Gland  magnified  forty- 
diameters. 


526.  Describe  the  perspiration.  What  two  forms  of  it? 


02 


II  1 T C n C O C K ’ S A N A T O Y 


527.  Amoiiiil  of  Watery  Vapor  Discharged  from  the 
Body, — The  amount  of  fluid  which  is  lost  from  the  body  both 
by  the  skin  and  lungs,  is  about  eighteen  grains  per  minute, 
eleven  by  the  skin  and  seven  by  the  lungs.  This  amount, 
however,  varies  exceedingly  with  the  state  of  the  health  and 
the  dryness  or  moisture  of  the  air,  which,  as  already  men- 
tioned, regulates  the  temperature  of  the  system. 

528.  The  Hair. — The  hair  is  distributed  over  nearly  every 
portion  of  the  human  frame,  and  presents  difierences  according 


Fig.  294. 


Sections  of  Human  Hair,  a,  5,  Trans- 
verse Sections  showing  the  Cortical  (or 
external)  and  Medullary  (or  internal)  Sur- 
face. c,  rf,  Longitudinal  Sections  of  Hair. 
d.  Shows  the  overlapping  of  the  Epidermic 
Scales  of  which  hair  is  composed. 

the  true  skin,  as  is  seen  in  Fig 
epidermis  one  or  more  glands  i 


to  age,  sex,  race,  or  individ- 
ual peculiarities.  In  length, 
the  hair  is  most  fully  devel- 
oped on  the  heads  of  females, 
sometimes  equaling  the  length 
of  the  body,  while  in  male 
beards  it  seldom  reaches  to 
the  waist.  The  coarsest  hair 
is  also  found  on  women. 

529.  Size  of  the  Hair — 
Oil  Glands . — In  diameter  the 
hair  varies  from  yjoth  to 
2oVoth  of  an  inch,  and  its 
section  is  always  of  an  oval 
outline,  but  never  circular. 
Nor  is  the  hair  of  a uniform 
diameter,  but  it  is  spindle- 
shaped  almost  always,  and 
terminates  in  a point.  At  its 
base  it  expands  into  a bulb 
which  is  lodged  in  a sac  in 
295,  p.  303.  Just  beneath  the 
re  situated  which  empty  their 


r>27.  Wluit  i.s  the  amount  of  walcry  Ihiid  discharged  from  the  body?  528.  What  is  said 
of  the  distrihution  of  the  hair?  JIow  long  has  tlie  liuir  ])ci‘n  known  to  grow?  529. 
What  is  the  diameter  of  tlie  hair?  What  is  the  ehaj^e  of  it?  What  glands  empty  their 
contents  upon  the  base  of  each  hair? 


AND  PHYSIOLOGY. 


303 


contents  into  the  same  pore  in 
■which  the  hair  itself  is  lo- 
cated. This  secretion  is  an  oil 
which  keeps  the  hair  in  a 
smooth  and  moist  state. 

530.  Tlicir  Number. — The 
number  of  the  hairs  varies 
with  the  color  and  portion  of 
the  body.  In  one  case  there 
were  found  on  the  same  sur- 
face 147  black  hairs,  162 
brown,  and  182  blonde.  On 
a surface  one  fourth  of  an 
inch  square  the  same  author 
found  on  the  scalp  293  hairs 
and  on  the  chin  39. 

Layer  from 

531.  Their  Distribution 
and  Direction —They  are 
implanted  either  singly  or  in  twos  or  threes,  or  even  four 
or  five  together,  and  their  direction  is  rarely  perpendicular 
to  the  skin,  being,  in  a natural  state,  downwards.  They  may, 
however,  be  changed  in  their  direction  by  persevering  efforts, 
as  is  sometimes  seen  by  the  brushing  of  the  hair  away  from 
the  forehead. 

532.  Chemical  Composition— Dnrabillty.— They  differ 
from  most  tissues  of  the  body  by  containing  ten  per  cent,  of 
sulphur.  This,  together  with  the  fact  that  they  contain  a 
large  per  cent,  of  nitrogen,  accounts  for  the  unpleasant  odor 
given  off  while  burning.  They  resist  decomposition  better 
than  most  of  the  tissues.  Those  of  Egyptian  mummies  re- 
main quite  unchanged.  And  it  is  owing  to  their  durability 
that  they  are  used  as  relics  of  departed  friends. 


l.  295. 


).  a,  Oil  Glands. 


530.  What  is  said  of  the  number  of  hairs  on  the  body?  531.  How  are  they  distributed, 
and  what  direction  do  they  take  ? 532.  How  do  they  differ  from  most  other  tissues  in 
chemical  composition?  How  durable  is  hair? 


804  HITCH  cock’s  anatomy 

533.  Constiliilion.  — In 
constitution  the  hair  con- 
sists of  three  distinct  por- 
tions, an  epidermis  or  outer 
portion,  a fibrous,  and  a med- 
ullary portion.  The  epider- 
mis is  arranged  in  the  form 
of  ring-like  scales,  wliicli 
overlap  each  other  like  the 
shingles  of  a house,  and  is 
about  ioVoth  of  an  inch 
thick  (Fig.  294,  rfj.  Hence 
we  see  the  reason  why  we 
can  brush  the  hair  in  only 
one  direction.  The  fibrous 
portion  makes  up  the  prin- 

Iliglily  Magnified  Root  of  Hair,  a.  Shaft  cipal  bulk  of  the  hair,  and 
of  Hair,  5,  c,  Epidermic  Sheath  of  Hair,  i r*  i • i • i 

Dermic,  or  External  Sheath  of  Ilair.  e,  Epi-  IS  COmpOSed  ot  lOUgltudinal 

dermic  Scales.  cells,  wliicli  Contain  paint 

granules  and  air  cavities  which  give  the  color  to  the  hair. 
The  medullary  portion  constitutes  the  central  part  of  the  hair 
(usually  from  one  third  to  one  fifth  its  diameter),  and  is  made 
up  of  cells  varying  in  diameter  from  e e o of  an 

inch  in  diameter. 

533  a.  Color. — The  color  of  the  hair  is  thought  by  some 
to  be  owing  to  the  iron  contained  in  it,  since  it  is  said  that 
there  is  the  most  of  this  metal  in  the  darkest  hair. 

533  b.  Pliysical  Properties.' — Hair  is  so  elastic  that  it 
will  stretch  without  breaking  to  nearly  one  third  more  than 
its  original  length.  A single  hair  of  the  head  will  support 
six  ounces  without  breaking.  It  readily  absorbs  moisture, 
and  is  dry  and  brittle  or  moist  and  soft,  according  as  the  skin 
or  atmosphere  is  dry  or  moist.  The  beard  is  abundantly 


Fig.  296. 

c b a be 


r.dfl,  Wliat  tlirec  portWms  is  oac-li  lialr  coiistiUitod  of?  Wliat  makes  the  principal  jiart 
<ifcaclj  liair?  M',]  a.  Wliat  is  it  iK)ssiblo  that  the  color  of  the  liair  is  owing  to?  503  5 
Wliat  Is  the  strcngtli  of  the  hair? 


AND  PHYSIOLOGY. 


805 


supplied  with  blood-vessels,  as 
is  seen  by  the  cut. 

533  c.  Rale  of  Growth. — ■ 

In  one  set  of  experiments 
the  hair  has  been  found  to 
grow  seven  lines  per  month. 

Frequent  shaving  greatly 
increases  its  growth.  It  also 
grows  faster  by  day  than 
by  night,  and  in  summer 
than  in  winter. 

of  the  Beard,  with  the  Arteries  supplying  it~very  highly  Magnified.  1,  Its  Follicle.  2, 
Its  Pulp.  3,  The  Trunk  of  the  Hair  without  the  Follicle.  4,  4,  Two  Arteries  going 
to  the  Base  of  the  Follicle.  5,  5,  Their  Distribution.  6,  6,  The  Reticulated  Tissue  of 
the  Follicle. 

FUNCTIONS  OF  THE  SKIN. 

534.  The  Skin  a Covering, — The  skin  is  the  natural  cov- 
ering of  the  body  of  man,  and  he  is  not  furnished  with  any 
further  and  more  complete  covering,  as  is  the  case  with  many 
of  the  lower  animals,  since  he  is  endowed  with  an  ability  to 
devise  means  of  covering  better  suited  to  his  condition  than 
one  of  hair,  wool,  or  feathers. 

535.  Use  of  the  Epidermis — To  Protect  the  Nerves. — 
The  epidermis  is  of  use  to  protect  the  corium  and  its  vessels. 
Without  this  covering  many  of  our  sensations  acquired  through 
the  ‘skin  would  be  very  painful.  The  contact  of  the  softest 
Eider  down  with  the  exposed  nervous  filaments  would  impart 
the  acutest  pain,  and  the  rays  of  the  noonday  sun  would  in- 
flict the  keenest  torture.  The  body  could  not  endure  the 
lightest  clothing,  and  even  our  motion  through  the  air  would 

533  c.  What  is  said  of  the  rate  of  growth  of  the  hair?  534.  What  is  said  of  the  skin  as 
a covering?  535.  What  is  said  of  the  epidermis  as  a source  of  protection  to  the  delicaLo 
nerves  of  touch  ? 


Fig.  29t. 


A small  portion  of  the  Follicle  of  a Hair 


806 


HITCHCOCK’S  A N A T O IS!  Y 


bo  a source  of  misery.  But  these  delicate  nerves  are  pro- 
tected by  an  insensible  membrane,  which,  though  hard,  elas- 
tic, and  a very  perfect  guard  of  these  faithful  sentinels,  per- 
mits all  the  necessary  impressions  to  pass  through  them.  The 
epidermis  also  guards  the  most  delicate  parts  in  a careful  man- 
ner,'by  thickening  its  substance  over  the  ends  of  the  fingers, 
and  in  all  places  where  sensation  is  most  acute.  It  is  also 
speedily  renewed  where  friction  or  accident  removes  it,  as  on 
the  palms  of  the  hands  and  soles  of  the  feet. 

536.  To  prevent  Absorption. — Another  important  use  of 
the  epidermis  is  to  prevent  undue  absorption.  For  the  lym- 
phatics only  penetrate  the  corium,  and  cease  at  the  under  sur- 
face of  the  epidermis.  Consequently  but  very  little  fluid  can 
enter  these  vessels  unless  the  epidermis  is  removed  or  satu- 
rated with  fluid.  Were  it  not  for  this  protection,  almost  every 
liquid  substance  brought  in  contact  with  the  surface  of  the 
body  would  at  once  be  introduced  into  the  general  circulation, 
thus  exposing  the  system  to  serious  danger  by  absorbing  poi- 
sonous matter. 

537.  To  Prevent  Excessive  Perspiration. — Danger  from 
an  opposite  direction  is  also  warded  off  by  the  impenetrability 
of  the  epidermis.  Were  it  not  for  the  tortuous  direction  which 
the  outlets  of  the  sweat  glands  take  as  they  empty  themselves 
upon  the  surface  of  the  body,  an  excessive  amount  of  water 
would  be  set  free,  and  thus  greatly  reduce  the  system.  But 
owing  to  this  arrangement  of  sweat  ducts,  it  is  only  when  the 
system  is  very  much  stimulated  that  any  considerable  amount 
of  water  can  be  discharged  by  sweating.  Were  not  this  the 
case,  the  body  would  often  be  reduced  to  a low  state  from  the 
loss  of  the  watery  portion  of  the  blood,  as  is  sometimes  seen 
in  excessive  sweating. 

538.  Use  of  llie  Coriiiiii  — Contains  tlie  Blood-Vessels 


Wliivt  l.s  tlio  uso  of  tlio  epidermis  to  prevent  nndno  absorption  ? 637.  How  does 
tlio  epidermis  prevent  undue  perspiration?  What  liarm  would  result  from  excessive 
sweating? 


AND  PHYSIOLOGY. 


07 


and  Nerves — Amount  of  Waste  Escaping  from  the  Skin. 

’ — In  the  cerium,  or  internal  layer  of  the  skin,  resides  the  vi- 
tality. Here  the  arteries  terminate  in  the  capillaries  and  the 
nerves  double  upon  themselves^  producing  the  highest  sensi- 
bility to  external  impressions.  So  that  when  any  function  of 
the  skin  is  spoken  of,  reference  is  usually  made  to  this  inner 
layer.  And  we  see  that  the  skin  is  not  only  useful  as  a pro- 
tection and  covering  to  the  body,  but  is  of  great  value  as  an 
excretory  apparatus.  And  in  this  ofiSce  the  skin  is  pecu- 
liarly valuable,  since  it  removes  a great  amount  of  matter 
from  the  system  that  the  lungs  cannot  remove.  The  actual 
amount  of  w^aste  matter  escaping  daily  from  the  skin  is  given 
variously  by  different  writers.  All,  however,  make  out  an 
average  of  from  thirty  to  forty  ounces,  or  if  condensed  to 
water,  about  two  pints.  A proof  that  the  vapor  of  water  es- 
capes in  the  form  of  insensible  perspiration  is  had  by  placing 
the  dry  hand  upon  a cold  glass  or  polished  metallic  substance, 
when  moisture  in  a few  seconds  condenses  on  the  surface. 

539.  Uses  of  the  Oil  Glands— Renders  the  Hair  Soft 
— Softens  the  Skin  — Protects  the  Eye  — Guards  the 
JI  e ill  b r a n a T y m p a n i . — The  function  of  the  sebaceous,  or  oil 
glands  of  the  skin  seems  to  be  the  secretion  of  substances  pro- 
tective to  the  skin.  These  are  mainly  oily  products,  and  are 
given  off  at  the  roots  of  the  hair,  so  as  to  give  it  flexibility, 
that  by  its  stifihess  it  may  not  irritate  the  skin.  The  oil  tubes 
are  most  abundant  on  those  parts  of  the  body  which  are  most 
exposed,  and  especially  the  face  and  neck.  The  design  of  the 
secretion  seems  to  be  to  give  flexibility  to  the  skin,  to  prevent 
the  heat  and  air  from  drying  it  so  that  it  would  crack  in  many 
places,  and  also  to  lubricate  it  when  brought  into  contact  with 
foreign  substances,  as  is  the  case  so  frequently  with  the  hands. 
The  oil  of  the  skin  also  prevents  moisture  from  adhering  to  it, 
and  thus  its  functions  can  be  more  perfectly  carried  on,  and 

538.  Where  lies  the  vitality  of  the  skin  ? What  other  use  than  a protection  is  the 
skin?  How  much  waste  matter  escapes  daily  from  the  skin?  How  many  pints  ? 539. 
What  is  the  use  of  the  oil  glands?  How  does  it  affect  the  hair?  What  value  does  it 
impart  to  the  skin  ? 


308 


HITCHCOCK’S  ANATOMY 


it  will  not  retain  all  dust  which  chances  to  fall  upon  it.  At 
the  flexions  of  the  joints,  and  all  those  places  where  two  sur- 
faces of  the  skin  are  frequently  brought  in  contact,  this  oily 
secretion  is  abundantly  poured  out,  in  order  that  there  may 
be  as  little  friction  as  possible  between  the  opposing  surfaces. 
Upon  the  edges  of  the  eyelids  is  situated  a row  of  glands  which 
pour  out  their  secretion  in  such  a manner  as  to  retain  the  tears 
— the  lubricating  fluid  of  the  eye — when  produced  in  their 
ordinary  quantity ; but  when  in  excess,  as  in  weeping,  they 
run  over  their  boundaries,  and  flow  down  the  cheek.  The  use 
of  these  glands  may  be  well  appreciated  in  some  diseases  of 
the  eye,  where  the  tears  constantly  run  down  upon  the  check, 
producing  irritating  sores. 

In  the  passages  of  the  ears  we  find  the  same  glands,  al- 
though their  secretion  is  of  a somewhat  different  character. 
Here  it  is  a clammy,  viscid  substance,  of  a yellowish  color, 
and  from  its  appearance  it  is  called  the  wax  of  the  ear.  Its 
service  is  to  prevent  dust  and  foreign  substances  generally 
from  gaining  access  to  the  internal  ear,  where  they  would 
injure  the  sense  of  hearing. 


HYGIENIC  INFERENCES. 

540.  — 1.  Great  Value  of  this  Membrane  in  the  Ani- 
mal Economy. — From  the  complicated  structure  of  the  skin, 
we  see  that  this  membrane  is  of  great  service  in  the  animal 
economy.  It  stands  next  in  importance  to  the  lungs  as  an 
excretory  organ,  and  if  its  functions  are  interrupted  the  whole 
system  very  soon  feels  the  disturbance. 

541.  — 2.  Its  Health  Requires  Cleanliness. — The  skin 
must  be  kept  clean  to  secure  the  proper  functions  of  the  per- 
spiratory glands.  This  not  only  implies  the  necessity  of  fre- 

1I(>\T  (Iocs  it  nfFo(^t  tlio  skin  at  the  joints?  Of  what  service  is  it  to  the  eye?  Of  what 
to  the  car  ? 510.  State  tlio  relative  value  of  the  skin  in  the  animal  economy.  541.  Why 
i.s  cleanlines.s  essential  for  the  health  of  the  skin  ? 


AND  PHYSIOLOGY. 


309 


quently  washing  the  whole  surface  of  the  skin,  but  also  the 
frequent  change  of  the  bed-clothes,  under-clothes,  etc.  And 
it  should  be  a fixed  rule  with  every  one  to  change  the  linen 
and  under-garments  both  night  and  morning  ; that  is,  the 
under-garment  worn  during  the  day  should  not  be  worn  at 
night,  and  the  reverse. 

542.  — 3.  Must  be  Kept  at  a Uniform  Temperature.— 
We  also  learn  that  the  skin  should  be  kept  at  a uniform  tem- 
perature, and  up  to  its  normal  standard.  It  therefore  needs 
proper  clothing,  not  so  much  in  the  coldest  weather — for  then 
our  feelings  will  impel  us  to  do  it — ^but  at  the  changes  of  tem- 
perature so  common  and  so  great  in  our  climate  in  spring  and 
autumn,  for  then  we  are  too  apt  to  neglect  it  because  we  feel 
no  especial  inconvenience,  and  yet  at  these  times  there  is 
more  danger  of  disease  from  a want  of  proper  clothing  than 
at  any  other  season  of  the  year.  We  seldom  injure  ourselves 
by  too  much  clothing,  because  we  can  easily  throw  of  superflu- 
ous garments,  but  often  do  it  by  too  small  an  amount  of  pro- 
tection. An  important  rule  for  every  one  is,  when  going 
abroad  even  a short  distance  from  home,  to  carry  with  him 
an  over  garment  when  exposed  to  evening  air. 

543.  — 4.  Must  Come  in  Contact  with  the  Air.— The 
skin  imbibes  oxygen  from  the  air,  and  hence  it  is  important 
that  air  be  brought  in  contact  with  this  membrane.  The 
clothing  should  be  worn  so  loosely  that  a thin  layer  of  air  will 
be  in  contact  with  nearly  every  part  of  the  skin. 

544.  — 5.  Needs  Friction. — Frequent  and  thorough  dry 
friction  applied  to  every  part  of  the  skin  greatly  promotes  the 
health,  not  only  of  this  membrane,  but  of  the  whole  body.  So 
smooth  are  the  clothes  we  generally  wear  next  the  skin,  that 
but  little  stimulus  is  received  by  them,  and  hence  a thorough 


542.  What  is  necessary  for  the  temperature  of  the  skin,  especially  for  changes  in 
weather?  What  is  said  of  an  over-coat  as  a constant  traveling  companion  ? 543.  Why 
should  the  skin  have  air  in  contact  with  it  ? 544.  What  is  the  use  of  friction  to  th® 
skin  ? 


310 


HITCHCOCK’S  ANATOMY 


rubbing  of  the  whole  body  every  night  and  morning  will  aid 
greatly  in  this  matter. 

545.  — 6.  Injurious  Effects  of  Moisture  upon  the  Skin. 
— Moisture  if  applied  to  the  skin  for  a considerable  length  of 
time  interrupts  its  functions,  and  accordingly  we  infer  that 
wet  or  damp  clothing  should  not  be  allowed  to  remain  on  the 
body  any  longer  than  is  absolutely  necessary.  If,  however, 
dry  clothing  cannot  be  procured  immediately,  the  body  should 
be  kept  in  vigorous  action  of  some  kind  until  the  clothes  can 
be  changed.  This  inference  is  of  equal  application,  whether 
the  whole  of  the  body  be  wet,  or  only  a portion  of  it,  as  the 
feet. 

546.  — 7.  Service  of  a Daily  Cold  Water  Bath. — We  in- 
fer again  that  a daily  cold  water  bath  is  of  great  service  for 
all  students  and  sedentary  persons  who  are  in  health.  Not 
only  is  it  desirable  on  account  of  cleanliness,  but  a serviceable 
shock  is  thus  imparted  to  the  nervous  system.  It,  however, 
should  be  taken  as  speedily  as  possible,  the  essential  thing 
desired  being,  that  pure  water  should  be  spread  over  the 
whole  surface  of  the  body,  and  after  it  that  the  skin  should 
be  speedily  and  vigorously  wiped  dry.  The  secondary  effect, 
however,  the  stimulus  imparted  to  the  nervous  system  by  the 
shock,  is  by  no  means  an  unimportant  issue  to  be  gained. 


COMPARATIVE  DERMATOLOGY. 

547.  Covering  of  Mammals, — The  skin  of  mammals  very 
closely  resembles  that  of  man,  with  the  exception  of  the  epi- 
dermis and  its  horny  appendages,  which  are  usually  covered  by 
hair.  The  fat  tissue,  too,  just  beneath  the  skin,  is  often  develop- 
ed in  a surprising  degree,  and  the  corium  in  many  instances  is 
very  thick.  Some  have  horny  scales,  and  others  long  plates. 


rur>.  Wlifit  nro  the  iiijiirioiis  ciructs  of  too  much  moisture  applied  to  the  skin?  546. 
What  Irt  said  of  a daily  hat li,  and  what  regulations  concerning  it?  547.  What  is  said  ol 
the  covering  of  mammals? 


AND  PHYSIOLOGY. 


Sll 


548.  Callosities. — In  many  of  the  rodent  or  gnawing  ani- 
mals, the  carnivora  and  camels,  the  epidermis  about  the  joints 
becomes  very  thick,  making  callosities  or  pads  for  the  sup- 
port and  protection  of  the  parts  exposed. 

549.  Epidermic  Scales. — True  Epidermic  Scales  are  found 
on  the  tails  of  many  animals,  such  as  the  Beaver. 

550.  Horn  of  Rhinoceros,— The  so-called  horn  of  the 
Khinoceros  is  nothing  but  a thickening  of  the  epidermis  until 
is  assumes  the  form  of  a hollow  cone. 

551.  Varieties  of  Hair.^The  hairs  upon  the  external 
surface  of  mammals  either  present  no  greater  irregularities 

Pig.  298.  Fig.  299. 


Hair  of  Sable.  Hair  of  Musk  Deer. 

than  do  those  of  man,  or  they  are  slightly  rough,  like  those 
of  the  Squirrel,  or  knotty,  as  in  the  Bear,  or  furnished  with 
pointed  processes,  like  the  teeth  of  a saw,  in  other  animals. 
Some  of  these  peculiarities  are  exhibited  in  the  adjoining 
cuts.  The  spines  of  the  Porcupine  and  Hedgehog  differ  from 
hairs  only  that  they  contain  the  same  materials  in  a more  con- 
densed form. 

552.  Glands  of  the  Skin.  — Cutaneous  and  sebaceous 
glands  are  present  in  most  mammals  very  abundantly.  The 


548.  To  which  membrane  of  the  skin  do  the  callosities  of  camels,  etc.,  belong?  519. 
Where  are  epidermic  scales  found?  650.  What  is  the  horn  of  the  rhinoceros?  551.  What 
are  the  varieties  of  hair  in  different  animals?  652.  What  is  said  of  glands  of  the  skin 


312 


HITCHCOCK’S  ANATOMY 


Fig.  300. 


Fio.  301. 


Transverse  Section  of  Hair  of  Pccftrl, 


A.  B,  Hairs  of  Squirrel.  C.  Hair  of  Indian  Bat. 

latter  secrete  an  unctions  fluid,  which  is  usually  of  a strong 
smell. 

553.  Skin  of  Birds. — The  Skin  of  Birds  is  thin  and  desti- 
tute of  cutaneous  glands,  except  one  at  the  tail,  which  is  gen- 
erally present.  The  whole  body  is  covered  by  feathers,  except 
certain  parts  of  the  head,  legs,  and  feet.  There  it  becomes  very 
much  thickened,  forming  callosities,  wattles  and  combs,  in 
which,  beside  the  cellular  tissue,  are  found  the  elastic  and  erec- 
tile tissues,  as  well  as  red  and  blue  cells  of  coloring  matter. 
Upon  the  toes  and  feet  are  found  plates  and  scales  of  horny  tissue. 

554.  Feathers  of  Birds. — The  Feathers  of  Birds  are 
made  up  of  the  Quill  and  Vane:  the  former  giving  it  attach- 
ment to  the  body,  and  the  latter  forming  its  expanded  surface. 
The  Vane  is  made  up  of  a small  number  of  laminae  or  plates, 
which  both  form  a light  and  firmly  resisting  medium  to  the 
air,  and  serve  to  retain  the  heat  within  the  body.  When  per- 
fectly formed  the  laminae  are  furnished  with  a booklet  at  their 
free  extremities,  by  which  they  are  attached  to  each  other, 

r>r)3.  What  is  tlio  tliickness  of  the  skin  of  birds  compared  with  that  of  mammals? 
What  are  the  wattles  and  combs?  5.51.  What  two  ]>arts  are  feathers  made  up  of?  Why 
are  the  lamina*,  furnished  with  a barb  at  each  extremity  ? What  is  the  design  of  their 
overlapping  each  other  ? 


AND  PHYSIOLOGY. 


313 


thus  making  each  feather  an  impenetrable  plane  surface. 
The  feathers  also  overlap  one  another  to  a considerable  de- 
gree, and  as  they  thus  contain  air,  and  are  themselves  non- 
conductors, they  afford  the  most  perfect  protection  to  the  body 
against  the  cold. 

555.  Skin  of  Amphibia. — The  naked  Amphibia,  such  as 
the  Frogs,  have  a smooth  slippery  skin,  which  is  continually 
being  cast  off  in  patches  or  shreds.  This  skin  surrounds  the 
solid  parts  of  the  body  very  loosely,  and  spaces  for  lymphatic 
vessels  are  found  beneath.  It  is  always  composed  of  several 
layers  of  fibres  which  lie  at  right  angles  with  each  other. 

556.  Scales  of  Serpents. — Upon  some  serpents,  scales  are 
found  which  overlap  one  another,  like  the  shingles  of  a house, 
as  is  also  the  case  with  fishes.  Scales  with  tubercular  spines 
are  met  with  on  some  reptiles,  and  in  some  instances,  as  those 
of  Crocodiles  and  Tortoises,  they  contain  bony  matter,  and 
coalesce  with  the  bones  of  the  skeleton. 

557.  Exnviation  of  Serpents. — Many  Serpents  cast  their 
skin  several  times  during  the  year,  either  by  piecemeal,  or  by 
drawing  off  the  whole  at  once.  One  species  of  Tortoise  does 
the  same  thing,  as  well  as  several  Lizards.  This  is  an  anal- 
ogous function  to  the  moulting  of  birds,  and  shedding  of  the 
coat  in  mammals.  This  generally  takes  place  in  Spring, 
but  frequently  upon  a change  of  weather  several  times  in  the 
year.  At  each  period,  when  this  is  effected  by  the  Rattle- 
Snake,  a new  segment  is  said  to  be  added  to  the  tail,  which 
seems  quite  probable,  since  the  rattle  is  merely  a condensed 
portion  of  the  epidermis. 

558.  Scales  of  Fishes. — Classification  of  Fishes  hy 
their  Scales. — Fishes  have  an  Epidermis  which  is  sometimes 
covered  with  scales,  and  sometimes  not,  though  always  lubri- 
cated most  thoroughly  by  a copious  mucous  secretion.  The 


555,  What  is  said  of  the  skin  of  frogs  ? 556.  Do  serpents  ever  have  scales  ? 557.  What 
is  tlic  exuviation  of  serpents?  When  does  this  take  place?  What  peculiarity  in  tho 
rattle-snake?  558.  How  are  tho  scales  of  fishes  arranged? 


314 


II  ITCH  cock’s  anatomy 


scales  are  sometimes  disposed  in  an  imbricated  manner  upon 
the  body,  and  are  not  situated  in  the  epidermis,  ‘‘but  really 
in  the  skin,  and  included  by  it.’’  The  scales  contain  both 
phosphate  and  carbonate  of  lime  as  a rule.  Their  shapes  arc 
various,  though  Professor  Agassiz,  the  best  living  authority 
on  fishes,  has  grouped  all  bony  fishes  under  four  orders,  de- 
pendent mainly  upon  the  form  of  the  scale.  First,  the  Pla- 
coidians,  including  such  fishes  as  the  Sharks  and  Rays,  where 
the  scales  are  cither  large  and  covered  with  bony  tubercles, 
or  simply  with  small  enameled  scales.  Second,  the  Ganoi- 
dians,  including  the  Sturgeon  and  bony  Pike,  which  have 
angular  bony  plates  coated  with  a thick  layer  of  enamel. 
Third,  the  Otenoidians,  such  as  the  Perch,  which  have  hard 
scales  jagged  on  the  outer  edges,  like  the  teeth  of  a comb. 
Fourth,  Cycloidians.  These  have  soft  and  circular  scales  with 
simple  margins.  In  this  order  are  found  the  Herring  and  Sal- 
mon. Sometimes  the  scales  are  provided  with  a hook-like 
process,  which  overlaps  and  fastens  itself  into  a depression  in 
the  scale  beneath. 

559.  Tegument  of  Articulata. — Horny  Case  of  In- 
sects.— The  Tegumentary  envelop  of  the  sub-kingdom  Arti- 
culata has  already  been  described  under  Comparative  Oste- 
ology, since  the  skin  of  many  of  this  sub-kingdom,  especially 
the  Crustacea  and  insects,  is  in  reality  the  only  skeleton  these 
animals  have.  Insects  have  a covering  sometimes  leathery 
and  soft,  and  sometimes  horny  and  solid,  which  contains  a 
peculiar  proximate  (chemical)  principle  known  as  Chitine. 

560.  Ill  nil  tie  of  Molluscs, — In  Molluscous  animals,  a 
dermis,  which  is  a muscular  skin,  envelops  all  the  viscera, 
and  hence  is  called  the  cloak  or  mantle,  which  secretes  tho 
hard  calcareous  covering  knoAvn  as  the  shell.  Generally  the 
shell  is  external  to  the  mantle,  as  in  the  Clam  and  Oyster, 

Wlifit  arc  1 ho  four  orders  (lopondont  upon  tlio  form  of  the  scale?  Who  is  the  author 
(.f  this  arrauj'cmcnt  ? (Jive  cxami)los  of  each.  559.  What  is  the  covering  of  the  articu- 
hii.a?  What  is  peculiar  about  its  chemical  composition?  560.  Describe  the  outside  cov- 
ering of  molluscs. 


AND  PHYSIOLOGY. 


315 


but  often,  as  in  the  Cypraea  or  Cowry,  the  mantle  extends 
over  the  shell. 

661.  Radiates. — With  the  exception  of  the  hard  external 
skeleton  of  these  animals  already  described,  their  proper  skin 
is  mostly  thin  and  soft,  allowing  of  great  flexibility  and  some- 
times of  great  expansion  and  contraction. 

The  Protozoa  have  a very  delicate,  cutaneous  envelope, 
sometimes  smooth  and  sometimes  covered  with  cilia. 

Effect  of  Fright  on  Hair. — A Sepoy  of  the  Bengal  Army,  brought  as  a 
prisoner  for  examination  before  the  British  officers,  was  terribly  affrighted, 
trembled  like  a lea^  and  was  almost  stupified  with  fear.  Such  was  the  shock 
upon  his  brain  that  his  hair,  from  a glossy  jet  black,  became  gray  within  the 
space  of  an  hour,  the  subject  being  only  twenty- four  years  of  age. 

Also  a boy,  let  down  from  a high  cliff  on  the  coast  of  Scotland  to  get  eggs 
of  sea-birds.  He,  in  defending  himself  from  the  birds  with  the  sword,  struck 
the  rope  by  which  he  was  suspended,  and  cut  off  every  strand  but  one. 
When  drawn  up  his  hair  was  white. 

Maria  Antoinette  experienced  a change  in  the  color  of  her  hair  during  one 
night’s  excessive  fear. 


CHAPTER  SEVENTH. 


THE  INSTRUMENTS  OF  ANIMATION.— NEUROLOGY,  OR 
THE  BRAIN  AND  NERVES. 


DEFINITIONS  AND  DESCRIPTIONS. 

562.  Main  Features  of  the  Nervous  System. — We 
now  come  to  an  organization  which  is  very  complicated  in 
structure,  some  of  whose  functions  are  the  most  obscure  of 
any  in  the  body.  It  is  called  the  Nervous  System  : and  the 
different  grades  in  the  animal  kingdom  are  established  by 
placing  those  having  the  most  complicated  nervous  system 
highest  on  the  scale.  Man  having  the  largest  brain  in  pro- 
portion to  the  rest  of  his  body,  and  possessed  of  the  greatest 
relative  amount  of  nerves,  is  therefore  placed  at  the  head  of 
the  animal  kingdom. 

563.  Microscopic  Structure. — Tubular  Portiou.— Diam- 
eter of  the  Tubes. — In  microscopic  structure  the  nervous 
tissue  presents  two  essential  elements : the  fibrous  or  tubular, 
which  is  mainly  found  in  the  nerve  trunks,  and  the  cellular  or 
vesicular,  existing  more  abundantly  in  the  ganglia  or  nerve 
centers.  In  the  former  the  tubes  are  the  largest  in  the  trunks 
of  the  nerves,  and  gradually  diminish  as  they  approach  the 
brain,  varying  in  size  from  the  2 oVoth-  the  2 t ^0 oth  of  an 
inch,  and  sometimes  existing  even  as  large  as  the  5^oth  of  an 
inch.  They  are  sometimes  conical  also,  measuring  at  one  end 
from  7 2*0  oth  of  an  inch  to  27 io  oth : the  smallest  end  being 
found  near  the  nerve  trunks,  and  are  sometimes  called  coarse 


502.  Olvo  tlio  leading  features  of  the  nervous  system.  6C3.  What  are  tlie  two  micro- 
scopic elements  of  nervous  tissue  ? Give  the  size  of  the  tubular  portion. 


AND  PHYSIOLOGY. 


317 


Pia  302. 


nerve  fibers.  These  fibers  have  the  appearance  of  a double  tube, 
or  a small  tube  within  a larger  one,  and  sometimes  exhibit  small 
nucleated  cells  within  the  two. 


564.  A closer  examination  shows  an  inner  or  grayish  por- 
tion which  is  called  the  axis  cylinder,  and  a white  substance 
around  this  called  the  medullary  matter,  or  substance  of 
Schwan,  and  outside  of  the  whole  a membranous  tube.  (Fig. 
302.)  They  are  often  called  Fine  Nerve  Fibers.  The  sym- 
pathetic system,  on  the  other  hand,  seems  to  be  made  up  of 
tubes  without  this  double  structure,  and  wdien  several  of 
them  are  joined  in  a bundle,  they  present  a grayish  appear- 
ance. They  are  also  of  a much  smaller  size,  varying  mostly 
from  Tilo  oth  to  g Ao^h  of  an  inch. 

565.  Vesicular  Structure. — The  vesicular  substance  is 
composed  of  cells  or  vesicles,  wdiich  present  very  curious 
forms,  being  somewhat  stellate  or  caudate.  The  central  por- 
tion is  globular,  consisting  of  a nucleated  cell,  which  sends 
off  processes  in  different  directions,  as  seen  in  the  annexed 
Figure  803.  Their  diameter  is  exceedingly  variable,  meas- 

W'hat  is  the  structure  of  the  sympathetic  system  ? 5G4.  What  still  more  minute  struc- 
ture can  be  detected  by  the  microscope  ? 5G5.  Describe  the  vesicular  structure.  Give 
the  diameter  of  the  cells. 


318 


HITCHCOCK’S  ANATOAtY 


Fia.  303. 


Vesicular  Nerve  Corpuscles,  a.  Cell  Wall.  h.  Cell  Contents,  c.  Pigment,  d.  Nu- 
cleus. e.  Prolongation  forming  Sheath  of  the  fiber.  /.  Nerve  Fiber,  magnified  350  diam- 
eter. 


uring  from  7 J oth  to  ^oVotli  of  an  inch.  These  are  found  in 
the  ganglia  and  the  substance  of  the  brain. 

566.  Divisions  of  the  Nervous  System. — The  nervous 
system  consists  of  a central  portion  contained  within  the  cav- 
ity of  the  skull  and  the  spinal  column,  and  a great  number 
of  white  threads  ramifying  through  every  part  of  the  body. 
The  physical  condition  upon  which  the  activity  of  the  ner- 
vous system  depends,  is  the  supply  of  arterial  blood. 

567.  Cerehriim, — If  we  examine  the  parts  wdthin  the  skull, 
(Fig.  304,  p.  319,)  we  shall  find  the  greater  mass  of  it  to  be 
of  a spheroidal  form,  divided  nearly  into  two  halves  by  a deep 
fissure  or  cleft,  and  its  surface  is  singularly  roughened  by 
elevations  and  depressions  called  anfractuosities. 

568.  This  mass  is  the  Cerebrum  or  Great  Brain,  and  the 
two  divisions  are  called  its  hemispheres.  (Fig.  307,  p.  321.) 

569.  In  man  the  average  weight  of  the  brain  is  fifty>four 
ounces,  in  females  forty-five;  the  maximum  being  sixty- four, 

500.  Wliat  i)rincipal  divisions  docs  tho  nervous  system  consist  of?  507.  Describe  the 
cerebrum.  509.  W hat  is  tho  average  weight  of  tho  braiu? 


319 


AND  PHYSIOLOGY. 


Fia.  304. 

a f h c 


Tertical  Section  of  the  Brain,  Cerebellum,  Pons  Yarolii,  and  Medulla  Oblongata, 
a,  Anterior  Lobe  of  the  Brain.  5,  Middle  Lobe,  c,  Posterior  Lobe.  Cerebellum,  e,  Me- 
dulla Spinalis,  f.  Section  of  the  Corpus  Callosum.  The  Lateral  Ventricles  of  the  Brain 
are  situated  on  either  side  of  the  Corpus  Callosum,  which  assists  in  forming  their  Upper 
'Wall,  gr,  Optic  Lobes:  1,  Olfactory  Nerves.  2,  The  Eyeball,  from  which  may  be 
traced  the  Optic  Nerve  as  far  as  the  Optic  Thalami  or  Lobes.  Close  to  this  is  the  Nerve 
of  the  Third  Pair.  4,  The  Fourth  Pair,  distributed,  like  the  Third,  to  the  Muscles  of  tlio 
Eyes.  5,  Superior  Maxillary  Branch  of  the  Fifth  Pair.  5',  Ophthalmic  Branch  of  the 
same  Pair  of  Nerves.  5",  Inferior  Maxillary  Branch  of  the  same  Pair  of  Nerves.  6,  Sixth 
Pair,  proceeding  to  the  Abducentes  Muscle.  7,  Facial  Nerve : — under  the  origin  of  this 
nerve  may  be  seen  a portion  of  the  Acoustic.  9,  Nerve  called  Glosso-Pharyngeal.  10, 
Pneumogastric  Nerve ; close  to  it  is  12,  the  Spinal  Accessory.  These  three  Nerves,  the 
Glosso-Pharyngeal,  Pneumogastric,  and  Spinal  Accessory,  are  by  some  reckoned  as  one 
pair.  11,  The  Ninth  Pair  of  some,  and  the  Eleventh  of  others,  called  also  Hypoglossal. 
14  and  15,  Cervical  Nerves. 

and  the  minimum  twenty ; the  average  capacity  of  the  cra- 
nia of  Germans  and  Anglo-Saxons  is  ninety  cubic  inches. 
Daniel  Webster’s  cranium  contained  122  cubic  inches. 

570.  Cerebellum, — The  Cerebrum,  by  a band  of  thick 
fibers,  is  connected  with  another  body,  of  a pear  shape,  at- 
tached to  it  by  its  base,  called  the  Lesser  Brain  or  Cerebel- 
1am.  (Big.  306,  p.  320.)  This  has  about  one  eighth  of  the 

State  tlie  average  capacity  of  Anglo-Saxon  crania,  and  also  that  of  Daniel  Webster. 
570.  Describe  the  cerebellum. 


14* 


320 


TI  I T 0 II  C O C K ’ S ANATOMY 


weight  of  the  Cerebrum,  and  lies  directly  behind  and  be- 
neath it. 


Fig.  305.  The  Lateral  Tentriclos  of  the 

CiTcbruin.  1,  1,  The  two  lloini- 
ppheres  cut  down  to  a level  with 
the  Cor[>us  Callosum,  so  as  to 
show  the  Centrum  Ovale  Majus. 
The  Surface  is  studded  with  the 
small  Puncta  Vasculosa.  2,  A 
small  portion  of  the  Anterior  Ex’ 
tremity  of  the  Corpus  Callosum. 
3,  Its  Posterior  Boundary ; the  in- 
termediate portion,  forming  the 
Eoof  of  the  Lateral  Ventricles,  has 
been  removed  so  as  to  completely 
expose  these  Cavities.  4,  A part 
of  the  Septum  Lucidum,  showing 
a space  between  its  Layers  which 
is  the  Fifth  Ventricle.  5,  The  An- 
terior Cornu  of  one  Side.  6,  The 
commencement  of  the  Middle 
Cornu.  7,  The  Posterior  Cornu. 
8,  The  Corpus  Striatum  of  one 
Ventricle.  9,  The  Taenia  Striata. 
10,  A small  part  of  the  Thalamus 
Opticus.  11,  The  Plexus  Cho- 
roides.  12,  The  Fornix.  13,  The 
commencement  of  the  Hippocam- 
pus Major  in  the  Middle  Cornu.  The  Pounded  Oblong  Body  in  the  Posterior  Cornu 
of  the  Lateral  Ventricle,  directly  behind  the  Figure  13,  is  the  Hippocampus  Minor.  A 
Bristle  is  seen  in  the  Foramen  of  Munro. 


Fig.  306. 


» 1 


A View  of  the  Interior  Surface  of  the  Cerebellum  and  a Portion  of  the  Medulla  Ob- 
longata. 1,  1,  The  Circumference  of  the  Cerebellum.  2,  2,  The  two  Hemispheres  of  the 
Cerebellum.  3,  Lobulus  Amygdaloides.  4,  The  Vermis  Inferior.  5,  Lobulus  Nervi 
Pneumogastrici.  6,  The  Calamus  Scriptorius.  7,  Its  Point.  8,  Section  of  the  Medulla 
Oblongata.  9,  Points  to  the  Origin  of  the  Pnoumogastric  Nerve. 


AND  PHYSIOLOGY 


321 


571.  Cerebral  Ganglia. — Also  lying  directly  upon  the 
base  of  the  brain,  are  found  several  distinct  enlargements  or 


Fig.  307. 


A View  of  the  Base  of  the  Cerebrum  and  Cerebellum,  together  with  their  Nerves. 
1,  Anterior  Extremity  of  the  Fissure  of  the  Hemispheres  of  the  Brain.  2,  Posterior  Ex- 
tremity of  the  same  Fissure.  8,  The  Anterior  Lobes  of  the  Cerebrum.  4,  Its  Middle 
Lobe.  5,  The  Fissure  of  Sylvius.  6,  The  Posterior  Lobe  of  the  Cerebrum.  7,  The 
Point  of  the  Infundibulum.  8,  Its  Body.  9,  The  Corpora  Albicantia.  10,  Cineritius 
Matter.  11,  The  Crura  Cerebri.  12,  The  Pons  Varolii.  18,  The  Top  of  the  Medulla 
Oblongata.  14,  Posterior  Prolongation  of  the  Pons  Varolii.  15,  Middle  of  the  Cerebel- 
lum. 16,  Anterior  Part  of  the  Cerebellum.  17,  Its  Posterior  Part  and  the.  Fissure  of  its 
Hemispheres.  18,  Superior  Part  of  the  Medulla  Spinalis.  19,  Middle  Fissure  of  the 
Medulla  Oblongata.  20,  The  Corpus  Pyramidale.  21,  The  Corpus  Restiforme.  22,  Tlia 
Corpus  Olivare.  28,  The  Olfactory  Nerve.  24,  Its  Bulb.  25,  Its  External  Root.  26, 
Its  Middle  Root.  27,  Its  Internal  Root.  28,  The  Optic  Nerve  beyond  the  Chiasm. 
29,  The  Optic  Nerve  before  the  Chiasm.  80,  The  Motor  Oculi,  or  Third  Pair  of  Nerves. 
81,  The  Fourth  Pair,  or  Pathetic  Nerves.  82,  The  Fifth  Pair,  or  Trigeminus  Nerves. 
83,  The  Sixth  Pair,  or  Motor  Externus.  84.  The  Facial  Nerve.  85,  The  Auditory — the 
two  making  the  Seventh  Pair.  36,  87,  33,  The  Eighth  Pair  of  Nerves.  (The  Ninth  Pair 
are  not  here  seen.) 


571.  What  are  the  cerebral  ganglia  ? 


322 


HITCHCOCK’S  ANATOMY 


ganglia,  the  most  important  of  which  are  the  Thalami  Optici, 
Corpora  Striata,  Olfactivc  Ganglia,  and  Tubcrcula  Quadrigc- 
mina. 


Fig.  308. 


572.  Spinal  Cord.— Upon  the  an- 
terior portion  of  the  Cerebellum, 
commences  the  Spinal  Cord,  the  up- 
per portion  of  which,  situated  within 
the  skull,  is  about  three  inches  in 
length  and  one  in  breadth,  and  is 
called  the  Medulla  Oblongata. 

573.  Ccrebro-Spinal  Center.— 
These  portions  of  the  nervous  sys- 
tem constitute  what  is  known  as  the 
Cerebro-Spinal  Axis  or  Center,  and 
are  all  made  up  of  two  kinds  of  mat- 


The  Cerebro-Spinal  Axis  seen  Anteriorly.  The 
Nerves  have  been  cut  through  at  a short  distance 
from  their  Origin  or  central  termination,  a,  The 
Cerebrum,  b,  Anterior  Lobe  of  the  Left  Hemisphere 
of  the  Brain,  c.  Middle  L(»be.  <7,  Posterior  Lobe,  al- 
most concealed  by  the  Cerebellum,  e,  The  Cerebel- 
lum. f,  The  Medulla  Oblongata  or  Bulb.  1,  First,  or 
Olfactory  Pair  of  Nerves.  2,  Second  Pair,  or  Optic. 

8,  Third  Pair,  or  Motores  Oculorum.  4,  Fourth  Pair, 
or  Pathetic.  5,  The  Facial,  or  Fifth  Pair.  6,  Sixth 
Pair,  or  Abducentes.  7,  Nerves  of  the  Seventh  Pair, 
or  Facial ; also  the  Acoustic,  or  Portio  Mollis,  by 
some  called  the  Auditory,  and  viewed  as  a division 
of  the  Seventh ; others  call  them  the  Eighth  Pair. 

9,  The  Glosso-Pharyngeal  Nerves,  called  the  Ninth 
Pair  by  some,  by  others  the  Anterior  Division  of  the 
Eighth  Pair.  10,  The  Pneurnogastric,  by  some  in- 
cluded in  the  Eighth  Pair,  by  others  called  the  Tenth 
Pair.  11,  Nerves  of  the  Eleventh  and  Twelfth  Pairs, 
the  first  being  viewed  by  some  as  a Division  of  the 
Eighth  Pair,  and  called  Spinal  Accessory;  the  latter, 
called  by  some  the  Ninth,  by  others  the  Twelfth,  is 

the  Motor  Nerve  of  the  Tongue.  13,  Nerves  of  the  Thirteenth  Pair,  or  Sub-Occipital.  14, 
15, 16,  The  First,  Second,  and  Third  Pairs  of  Cervical  Nerves,  g,  Cervical  Nerves  form- 
ing the  Brachial  Plexus.  25,  One  of  the  Pairs  of  Nerves  of  the  Dorsal  Portion  of  the 
Si)inal  Marrow.  83,  One  of  the  Pairs  of  Lumbar  Nerves,  h,  Lumbar  and  Sacral  Nerves 
forming  the  Plexus  whence  come  the  Nerves  of  the  Lower  Extremities,  i and  y.  Ter 
inination  of  the  Si)inal  Marrow,  called  Canda  Equina,  Great  Sciatic  Nerve  proceed- 
ing to  the  Lower  Extremities. 


572.  What  is  tlie  medulla  oblongata?  573.  What  two  kinds  of  matter  does  a slicing  of 
the  brain  show,  and  how  is  the  gray  and  white  matter  disposed? 


AND  PHYSIOLOGY. 


323 


ter ; the  gray  or  external,  and  the  white  or  internal.  This 
structure  is  best  seen  when  the  brain  is  cut  through  in  a hori- 
zontal direction;  the  gray  showing  itself  as  an  outside  layer 
with  an  irregularly  scolloped  edge,  while  the  white  is  internal, 
and  constitutes  the  greater  portion  of  the  whole  brain. 


574.  Blood-Vessels  of  the  Brain— Venous  Sinuses^ 
• — The  blood-vessels  of  the  brain  are  very  numerous,  since  one 
sixth  of  all  the  blood  is  sent  to  this  organ,  although  its  weight 
is  about  one  fortieth  of  the  body.  The  arteries  are  the  most 
numerous,  and  as  already  mentioned,  those  entering  the  head 
from  the  front  side  of  the  neck,  communicate  very  freely  with 
those  coming  in  at  the  back  side  of  the  head,  (see  Fig.  213), 
making  a perfect  circle  of  communication,  so  that  there  may 


be  no  impediment  to  the  cir- 
culation of  the  blood  through 
the  nervous  center.  The  veins 
are  not  numerous.  Some  are 
found  on  the  surface  of  the 
brain,  but  only  a few  pene- 
trate into  its  substance.  But 
large  channels  are  found  be- 
tween the  membranes  called 
Sinuses,  which  do  not  pre- 
sent the  ordinary  characteris- 
tics of  veins,  except  that  they 
convey  the  blood  to  the  heart. 
The  two  sinuses  which  are  of 
the  largest  size,  discharge 
their  contents  into  the  jugu- 
lar veins.  (Fig.  309.) 

575r  Membranes  of  the 
Cere bro- Spinal  Center. — 
Hura  Mater. — Three  mem- 


Fig.  309. 


Sinuses  of  the  Base  of  the  Skull.  1,  Oph- 
thalmic Veins.  2,  Cavernous  Sinus,  3, 
Circular.  4,  6,  Inferior  Petrosal.  5,  9,  Oc- 
cipital Sinuses.  7,  Internal  Jugular  Vein. 


574.  What  proportion  of  the  blood  goes  to  the  brain?  Which  are  the  most  numerous, 
the  arteries  or  the  veins  ? What  are  the  sinuses  found  there  ? 


324 


HITCHCOCK’S  ANATO:\[Y 


brancs  envelop  the  brain,  altliougli  to  the  unassisted  eye  they 
appear  as  one.  They  are  of  great  importance  in  the  economy 
of  the  brain,  and  are  often  the  seat  of  severe  disease.  The 
outer  one  is  called  the  Dura  Mater,  that  covers  both  the 
brain  and  spinal  cord,  and  is  attached  firmly  to  tlic  bones 
which  it  covers.  It  has  the  same  composition  as  the  liga- 
ments of  the  body — white  fibrous  tissue — and  consequently  is 
very  tough,  being  the  firmest  of  the  three  membranes. 

576.  Arachnoid  Membrane —The  Arachnoid  Membrane 
lies  directly  beneath  the  dura  mater,  and  receives  its  name 
from  the  Greek  word  signifying  spider’s  web. 

577.  Pi  a Mater. — Closely  beneath  it  is  the  Pia  Mater, 
which  lies  directly  upon  the  surface  of  the  brain,  and  dips 
into  all  the  cavities  or  convolutions  on  its  surface.  This 
membrane  is  especially  serviceable  in  the  nourishment  of  the 
brain,  and  receives  the  arteries  which  enter  at  the  anterior 
and  posterior  part  of  the  skull.  Its  nerves  are  branches  of 
the  sympathetic  system. 

578.  Surface  of  the  Brain. — The  surface  of  the  brain  is 
very  uneven,  being  covered  with  convolutions  or  tortuous 
ridges  and  corresponding  depressions,  the  design  of  which  is 
not  as  yet  well  known,  though  probably  merely  to  procure  a 
greater  amount  of  surface,  and  they  do  not  correspond  to  the 
irregularities  on  the  surface  of  the  skull  from  which  phre- 
nologists profess  to  judge  of  character. 

579.  Ventricles  of  the  Brain . — Within  the  brain  are  sev- 
eral cavities  called  ventricles,  of  which  the  special  use  has  not 
been  determined.  (Fig.  305,  p.  320.)  It  is  a curious  fact, 
however,  that  a post  mortem  examination  of  the  brain  of  in- 
ebriates frequently  discovers  these  cavities  to  be  partially  filled 
with  alcohol. 

580.  Division  of  the  Nerves. — All  the  nerves  that  pro- 

575.  How  injiny membranes  envelopin'^  the  brain?  Describe  the  dura  mater.  576. 
Describe  tlic  arachnoid  membrane.  577.  Describe  the  pia  Tnater.  What  are  its  nerves? 
578.  What  is  the  connitlon  of  the  surface  of  the  brain  ? 579.  What  are  the  cavities  in  the 
brain  called  ? 580.  How  arc  all  the  nerves  given  off  from  the  brain  and  spinal  cord  ? 


AND  PHYSIOLOGY. 


?25 


ceed  from  the  cerebro-spinal  axis  are  given  off  in  pairs  on 
opposite  sides  of  the  median  line  of  the  body.  They  are  di- 
vided into  two  sets  ; those  which  are  given  oflf  from  the  great 
brain,  little  brain,  and  medulla  oblongata,  being  called  cranial 
nerves^  and  those  from  the  spinal  cord,  spinal  nerves. 

581.  Cranial  Nerves, — Many  of  the  cranial  nerves,  and 
all  of  the  spinal  nerves,  arise  by  two  roots,  and  soon  form  a 
small  protuberance,  which  is  called  a Ganglion  or  knot,  in 
which  the  fibers  are  confusedly  mixed  together,  after  which 
they  proceed  in  the  same  sheath  to  their  destination. 

582.  Of  the  cranial  nerves  there  are  twelve  pairs,  named 
as  follows  : 


First  pair. . 

. .Olfactory. 

Seventh 

pair.  .Facial. 

Second  “ . . 

. .Optic. 

Eighth 

..Auditory. 

Third  “ ... 

. .Motores  Oculorura.  Ninth 

“ . . Glosso-  Pharyngeal . 

Fourth  “ . . 

. .Trochleares. 

Tenth 

“ ..ParYagi. 

Fifth  “ . . 

. .Trifacial. 

Eleventh 

“ . .Spinal  Accessory. 

Sixth  .., 

. .Abducentes. 

•Twelfth 

“ . .Lingual. 

583.  Olfactory. — The 

olfactory  nerves  arise  from  the  an- 

Fig.  310. 


A.  View  of  the  First  Pair,  or  Olfactory,  with  the  Nasal  Branches  of  the  Fifth.  1,  Fron» 
tal  Sinus.  2,  Sphenoidal  Sinus.  3,  Hard  Palate.  4,  Bulb  of  the  Olfactory  Nerve.  5, 
Branches  of  the  Olfactory  on  the  Superior  and  Middle  Turbinated  Bones.  6,  Spheno- 
palatine Nerves  from  the  Second  of  the  Fifth.  7,  Internal  Nasal  Nerve  from  the  First 
of  the  Fifth.  8,  Branches  of  Seven,  to  Schneiderian  Membrane.  9,  Ganglion  of  Cloquet 
KwWio,  foramen  inciHivium.  10,  Anastomosis  on  the  Inferior  Turbinated  Bone  of  the 
Branches  of  the  Fifth  Pair. 


What  are  the  two  principal  groups  of  nerves?  581.  How  many  roots  do  most  of  the 
nerves  have  ? 582.  How  many  pairs  of  cranial  nerves,  and  what  are  their  names  ? 


320 


HITCHCOCK’S  ANATOMY 


terior  portion  of  the  base  of  the  brain,  and  are  distributed 
upon  the  mucous  membrane  of  the  nostrils ; especially  that 
part  of  it  which  is  spread  out  upon  the  turbinated  bones. 


Fig,  311. 


A View  of  the  Second  Pair  or  Optic,  and 
the  Origin  of  Seven  other  Pairs.  1, 1,  Globe 
of  the  Eye.  The  one  on  the  left  hand  is  per- 
fect, but  that  on  the  right  has  the  Sclerotic 
and  Choroid  removed  to  show  the  Ketina.  2) 
The  Chiasm  of  the  Optic  Nerves.  3,  The 
Corpora  Albicantia.  4,  The  Infundibulum. 
5,  The  Pons  Varolii.  6,  The  Medulla  Ob- 
longata. The  figure  is  on  the  Right  Corpus 
Pyramidale.  7,  The  Third  Pair,  Motores 
Oculi.  8,  Fourth  Pair,  Pathetici.  9,  Fifth 
Pair,  Trigemini.  10,  Sixth  Pair,  Abducentes. 
11,  Seventh  Pair,  Auditory  and  Facial.  12, 
Eighth  Pair,  Pneumogastric,  Spinal  Acces- 
sory, and  Glosso-Pharyngeal.  13,  Ninth  Pair, 
Hypoglossal 


584.  Optic . — The  optic 
nerves  arise  at  a point  be- 
hind that  where  the  olfac- 
tories are  given  off,  and 
about  one  inch  from  this 
point  come  together  and 
form  a ganglion  ; after  this 
they  are  again  separated  and 
proceed  to  the  posterior 
portion  of  each  eye-ball^ 
where  they  are  expanded 
into  a membrane,  called  the 
Ketina.  (Fig.  311.) 

585.  Motores  OculoruHi. 

— The  third  are  also 

given  off  from  the  base  of 
the  brain  near  to  the  pons 
varolii,  and  are  sent  to  a 
part  of  the  muscles  of  the 
eye. 

586.  Troclileares  — The 
trochleares  have  nearly  the 
same  origin  as  the  last-men- 
tioned pair,  and  are  distrib- 
uted to  the  superior  oblique 
muscles  of  each  eye.  (Fig. 


312.) 

587.  Trifacial.— The  fifth  pair,  or is  the  largest 
of  the  cranial  nerves.  It  is  analogous  to  the  spinal  nerves  in 


Give  the  anatomy  of  the  olfactory  nerves.  584.  Describe  the  optic  nerves.  555. 
Describe  tlio  motores  oculorum.  686.  Give  the  anatomy  of  the  fourth  pair.  687.  De- 
Borlbo  the  trifacial. 


AND  PHYSIOLOGY. 


327 


A View  of  the  Third,  Fourth,  and  Sixth  Pairs  of  Nerves.  1,  Ball  of  the  Eye,  the  Rec- 
tus Externus  Muscle  being  cutand  hanging  down  from  its  origin.  2,  The  Superior  Max- 
illa, 8,  The  Third  Pair,  or  Motor  Oculi,  distributed  to  all  the  Muscles  of  the  Eye  except 
the  Superior  Oblique  and  External  Rectus.  4,  The  Fourth  Pair,  or  Patheticus,  going  to 
the  Superior  Oblique  Muscle.  5,  One  of  the  Branches  of  the  Fifth.  6,  The  Sixth  Pair, 
or  Motor  Externus,  distributed  to  the  External  Rectus  Muscle.  7,  Spheno-Palatine 
Ganglion  and  Branches.  8,  Ciliary  Nerves  from  the  Lenticular  Ganglion,  the  short  Root 
of  which  is  seen  to  connect  it  with  the  Third  Pair. 

A View  of  the  Distribution  of  the  Tri- 
facial, or  Fifth  Pair.  1,  Orbit.  2,  Antrum 
of  Highmore.  3,  Tongue.  4,  Lower  Max- 
illa. 5,  Root  of  Fifth  Pair,  forming  the 
Ganglion  of  Casser.  6,  First  Branch,  Oph- 
thalmic. 7,  Second  Branch,  Superior 
Maxillary.  8,  Third  Branch,  Inferior 
Maxillary.  9,  Frontal  Branch,  dividing 
into  External  and  Internal  Frontal  at  14. 

10,  Lachrymal  branch,  dividing  before  en- 
tering the  Lachrymal  Gland.  11,  Nasal 
Branch.  Just  under  the  figure  is  the  long 
Root  of  the  Lenticular  or  Ciliary  Ganglion, 
and  a few  of  the  Ciliary  Nerves.  12,  In- 
ternal Nasal,  disappearing  through  the 
Anterior  Ethmoidal  Foramen.  13,  Exter- 
nal Nasal.  14,  External  and  Internal 
Frontal.  15,  Infra-Orbitary  Nerve.  16, 

Posterior  Dental  Branches.  17,  Middle 
Dental  Branch.  18,  Anterior  Dental 
Nerve.  19,  Terminating  Branches  of  In- 
fra-Orbital, called  Labial  and  Palpebral. 

20,  Subcutaneous  Mal{e,or  Orbitar  Branch. 

21,  Pterygoid  or  Recurrent,  from  Meckel's 
Ganglion.  22,  Five  Anterior  Branches  of 
Third  of  Fifth,  being  Nerves  of  Motion, 
and  called  Massoter,  Temporal,  Ptergoid, 
and  Buccal,  23,  Lingual  Branch  joined  at  an  acute  angle  by  the  Chorda  Tympani.  24, 
Inferior  Dental  Nerve  terminating  in  25,  Mental  Branches.  26,  Superficial  Temporal 
Nerve.  27,  Auricular  Branches.  28,  Mylo-hyoid  Branch. 


Fig.  313. 


328 


HITCHCOCK’S  A N A T O Y 


Fm.  314. 


Distribution  of  the  Fifth  Pair  of  Nerves,  a,  Submaxillary  Gland.  1,  Small  Root  of 
the  Fifth  Nerve.  2,  Gasserian  Ganglion.  8,  Ophthalmic  Nerve.  4,  Upper  Maxillary 
Nerve.  5,  Lower  Maxillary  Nerve.  6,  Chorda  Tympani.  7,  Facial  Nerve. 

that  each  nerve  arises  by  two  roots,  and  afterwards,  before 
distribution,  forms  the  Gasserian  ganglion.  This  ganglion  is 
separated  into  three  branches  : the  ophthalmic,  which  supplies 
315.  the  region  of  the  eye  and 

nose  ; the  superior  maxil- 
lary, supplying  different 
parts  of  the  face  from  the 
temporal  muscle  to  the 

A View  of  the  Origin  and  Disiribu- 
tion  of  the  Portio  Mollis  of  the  Sev- 
enth Pair,  or  Auditory  Nerve.  1,  The 
Medulla  Oblongata.  2,  The  Pons  Var- 
olii.  8,  4,  The  Crura  Cerebelli  of  the 
Right  Side.  5,  Eighth  Pair.  6,  Ninth 
Pair.  7,  The  Auditory  Nerve  distrib- 
uted to  the  Cochlea  and  Labyrinth. 
8,  The  Sixth  Pair.  9,  The  Portio  Dura 
ef  the  Seventh  Pair.  10,  The  Fourth  Pair.  11,  The  Third  Pair. 


AND  PHYSIOLOGY. 


329 


Pig.  316. 


lips,  including  the  upper  teeth 
and  the  inferior  maxillary, 
sending  its  branches  to  the 
tongue,  cheeks,  and  anterior 
portion  of  the  face. 

588.  Abducentes.  — The 
sixth  pair,  abducentes^  are  sent 
from  the  medulla  oblongata  to 
the  external  muscle  of  the  eye. 

589.  Facial. — The  facial 
nerves  have  their  origin  in 
common  with  the  last  pair. 

They  join  with  some  of  the 
branches  of  the  fifth  pair,  and 
distribute  their  filaments  to 
some  of  the  muscles  of  the  face. 

590.  Auditory. — The  au- 
ditory nerves^  as  their  names 
imply,  are  sent  to  the  ear. 

They  enter  the  internal  ear 

Origin  and  Distribution  of  the  Tenth 
Pair  of  Nerves.  1,  3,  4,  The  Medulla  Ob- 
longata. 1 Is  the  Corpus  Pyramidale  of 
one  side.  3,  The  Corpus  Oblivare.  4,  The 
Corpus  Restiforme.  2,  The  Pons  Varolii. 

5,  The  Facial  Nerve.  6,  The  Origin  of  the 
Glosso -Pharyngeal  Nerve.  7,  The  Gang- 
lion of  Andersch.  8,  The  Trunk  of  the 
Nerve.  9,  The  Spinal  Accessory  Nerve. 

10,  The  Ganglion  of  the  Pneumogastric 
Nerve.  11,  Its  Plexiform  Ganglion.  12, 

Its  Trunk.  13,  Its  Pharyngeal  Branch 
forming  the  Pharyngeal  Plexus  (14),  as- 
sisted by  a Branch  from  the  Glosso- 
pharyngeal (8),  and  one  from  the  Superior 
Laryngeal  Nerve  (15).  16,  Cardiac  Branch- 
es. 17,  Recurrent  Laryngeal  Branch.  18, 

Anterior  Pulmonary  Branches.  19,  Posterior  Pulmonary  Branches.  20,  Esophageal 
‘Plexus.  21,  Gastric  Branches.  22,  Origin  of  the  Spinal  Accessory  Nerve.  23,  Its 
Branches  distributed  to  the  Sterno-Mastoid  Muscle.  24,  Its  Branches  to  the  Trapezius 
Muscle. 


5S8.  Describe  the  abducentes.  589.  Describe  the  facial  nerves.  590.  Describe  the  au- 
ditory nerves. 


030 


HITCHCOCK’S  ANATOMY 


after  receiving  fibers  from  the  facial,  and  there  divide  into 
two  branches,  which  are  distributed  in  the  irregular  labyrinth 
of  the  ear. 

591.  fi  1 0 s s 0 - P li  a r y n g e a I . — The  glosso-pharynjcal  makes 
the  ninth  pair,  and  is  sent  to  the  mucous  surface  of  the  fauces, 
tongue,  tonsils,  and  mucous  glands  of  the  mouth. 

592.  Par  Vagi,  or  Pneumogastric.— The  tenth  pair, 
vagum^  spring  from  the  medulla  oblongata,  and  after  giv- 
ing branches  to  several  of 
the  cranial  nerves,  are  dis- 
tributed upon  the  heart, 
lungs,  stomach,  and  nearly 
all  the  organs  of  the  tho- 
rax and  abdomen. 

593.  Spinal  Accessory. 
— The  spinal  accessory 
takes  its  origin  from  the 

The  Anatomy  of  the  side  of  the  Neck, 
showing  the  Kerves  of  the  Tongue.  1, 
A Fragment  of  tlie  Temporal  Bono 
containing  the  Meatus  Auditorius  Ex- 
ternus,  Mastoid,  and  Styloid  Process. 
2,  The  Stylo-Hyoid  Muscle.  3,  The 
Stylo-GIossus.  4,  The  Stylo-Pharyn- 
geus.  5,  The  Tongue.  6,  The  Hyo- 
Glossus  Muscle;  its  two  portions.  7, 
The  Genio-Hyo-Glossus  Muscle.  8, 
The  Genio-Hyoideus : they  both  arise 
from  the  inner  surface  of  the  Symphy- 
sis of  the  Lower  Jaw.  9,  The  Sterno- 
Hyoid  Muscle.  10,  The  Sterno-Thyroid.  11,  The  Thyro-Hyoid,  upon  which  the  Thyro- 
Ilyoidean  Branch  of  the  Hypoglossal  Nerve  is  seen  ramifying.  12,  The  Omo-Hyoid 
crossing  the  Common  Carotid  Artery  (13),  and  Internal  Jugular  Vein  (14).  15,  The  Ex- 

ternal Carotid  giving  olf  its  Branches.  16,  The  Internal  Carotid.  17,  The  Gustatory 
Nerve  giving  off  a Branch  to  the  Submaxillary  Ganglion  (18),  and  communicating  a little 
further  on  with  tne  Hypoglossal  Nerve.  19,  The  Submaxillary,  or  Wharton's  Duct, 

, jiassing  forwards  to  the  Sublingual  Gland.  20,  The  Glosso-Pharyngeal  Nerve,  passing  in 
behind  the  Hyo-Glossiis  Muscle.  21.  The  Hypoglossal  Nerve  curving  around  the  Oc- 
ci[>ital  Artery.  22,  The  Descendens  Noni  Nerve,  forming  a Loop  with  (23)  the  Coinmu- 
nicans  Noni,  which  is  seen  to  be  arising  by  filaments  from  the  Upper  Cervical  Nerves. 
24,  The  Pneumogastric  Nerve,  emerging  from  between  the  Internal  Jugular  Vein  and 
Common  Carotid  Artery,  and  entering  the  Chest.  25,  The  Facial  Nerve,  emerging  from 
the  Stylo-Mastoid  Foramen,  and  crossing  the  External  Carotid  Artery. 


Pig.  317. 


Describe  the  glosso-pharyngoal,  par  vagum,  and  spinal  accessory. 


AND  PHYSIOLOGY. 


331 


upper  part  of  the  spinal  column,  and  afterwards  enters  the 
cranium.  After  keeping  company  with  the  par  vagum  for  a 
part  of  its  course,  it  is  distributed  to  some  of  the  muscles  upon 
the  head  and  face. 


594.  Lingual. — The  Ungual  nerve  plunges  its  branches 
deeply  into  the  fibers  of  the  tongue,  and  communicates  with  a 
branch  of  the  trifacial. 


595.  Spinal  Cord, — The  spinal  cord 
is  that  portion  of  the  cerebro-spinal  axis 
contained  within  the  channel  made  by 
the  foramina,  or  openings  of  the  verte- 
bra. It  extends  from  the  medulla  ob- 
longata just  at  the  base  of  the  skull,  to 
the  second  lumbar  vertebra,  and  has  an 
average  diameter  of  half  an  inch.  It  Portion  of  the  Spmai  Cord, 

o niul  Origin  of  one  Pair  of 

has  the  general  appearance  of  a flattened  Nerves.  «,  spinai  cord.  &, 
cord,  but  on  a closer  inspection  it  ap-  interior  Root.  Trunk 
pears  to  be  made  up  of  two  smaller  cords,  forced  by  both.  /,  Branch, 
called  the  lateral  cords,  nearly  separated  by  two  clefts,  called 
the  anterior  and  posterior  median  fissures.  This  cord  is  not 
perfectly  uniform  in  its  size,  but  presents  two  enlargements, 
one  at  the  point  where  the  nerves  are  given  oS*  to  the  upper 
extremities,  and  the  other  near  the  lower  end  of  the  cord. 


Fig.  318. 


596.  Microscopic  Structure  of  the  Spinal  Cord.— In 
anatomical  structure  we  find  the  spinal  cord  and  spinal  nerves 
are  made  up  of  two  kinds  of  nervous  matter,  the  white  and 
the  gray,  and  also  that  each  pair  of  these  nerves  arises  by 
an  anterior  and  a posterior  root.  The  posterior  root  is  made 
up  of  gray  nervous  tissue,  and  is  called  the  sensitive  root, 
since  it  gives  the  sense  of  feeling  to  the  parts  where  it  is  dis- 
tributed ; the  anterior  root  of  white  fibers  is  called  the  mo- 
tor root,  because  it  imparts  motion  to  the  different  muscles  of 


594.  Describe  the  lingual.  595.  What  is  the  spinal  cord  ? Uow  many  fissures  has  the 
spinal  cord?  How  many  enlargements?  596.  What  is  the  microscopic  structure  of  the 
spinal  coni?  Which  is  the  sensitive  and  which  the  motor  root? 


332 


HITCHCOCK’S  ANATOLIY 


the  body.  A ganglion  is  found  upon  the  posterior  root,  just 
before  it  unites  with  the  anterior. 

597.  Origin  of  the  Spinal  Nerve s— Between  each  of 
the  vertebrae  the  spinal  nerves  are  given  off.  These  arc  made 
up  of  fasciculi,  and  each  fasciculus  of  distinct  fibers  which 
somewhat  resemble  muscular  fiber.  They  arise  on  each  side 
of  the  cord  by  two  roots,  one  given  off  from  the  anterior  and 
the  other  from  the  posterior  part  of  the  lateral  cords ; the 
anterior  root  being  the  one  that  is  designed  to  produce  mo- 
tion, and  the  posterior  giving  sensation  to  the  parts  on  which 
it  is  distributed.  These  two  roots  unite  as  soon  as  they  have 
fairly  left  the  spinal  cord,  after  which  they  proceed  as  a single 
nerve.  (See  Fig.  318.) 

Fig.  319.  598.  Groups  of  Spinal  Nerves —These 

nerves  are  grouped  together,  and  have 
the  same  name  as  the  groups  of  verte- 
brae in  which  they  are  located. 

8 Cervical.  6 Lumbar. 

12  Dorsal.  6 Sacral. 

The  last  nine  are  additional,  or  supple- 
mentary to  the  spinal  cord,  and  not  prop- 
erly a portion  of  it.  They  are  called 
the  cauda  equina. 

599.  Plexuses . — Most  of  these  nerves 
are  grouped  together  soon  after  leaving 

Diagram  to  show  the  De.  Spinal  column,  each  group  being 

cassation  (crossing  from  called  a plcxus  (from  the  Greek  to 

side  10  side)  of  Nerve  Fi-  n\  i i i 

bers  in  a Nerve.  wcave''),  which  IS  Simply  a net-work  of 

nervous  fibers.  Although  there  is  to  the  naked  eye  a com- 
plete interlacement  and  an  apparent  loss  of  fiber,  yet  by  the 
microscope  these  fibers  can  be  distinctly  traced  through  the 
whole  mass,  with  the  exception  of  a few  which  are  inter- 
changed for  purposes  to  be  described  hereafter.  After  emerg- 

r/iZ.  Give  the  origin  of  the  spinal  nerves.  598.  State  the  groups  of  the  spinal  nerves, 
599.  Describe  the  nature  of  the  plexuses. 


AISTD  PHYSIOLOGY 


333 


Fig.  320. 


Nervous  System. 

a,  Brain.  Little  Brain,  c,  Spinal  Marrow,  d,  Facial  Nerve,  e,  Brachial  Plexus, 
caused  by  the  union  of  several  Nerves  coming  from  the  Spinal  Marrow,  f,  Median  Nerve. 
g,  Cubital  Nerve.  A,  Internal  Cutaneous  Nerve  of  the  Arm.  i,  Kadial  and  Musculo- 
cutaneous Nerve  of  the  Arm.  Intercostal  Nerves,  Femoral  Plexus.  ^ Sciatic 
Plexus,  w,  Tibia!  Nerve,  n,  External  Peroneal  Nerve  ; o,  External  Saphenous  Nerve. 


334 


HITCHCOCK’S  ANATOMY 


ing  from  the  plexuses,  the  nerves  proceed  to  their  destination 
and  receive  names,  many  of  which  are  the  same  as  the  arteries 
which  they  accompany. 

600.  Cervical  Plexus  — Brachial  Plexus  — Lumbar 
Plexus  — Sacral  Plexus . — The  cervical  plexus  is  made  up  of 
the  four  upper  cervical  nerves,  and  the  brachial  plexus  of  the 


Fio.  321. 


Fia  322. 


A View  of  the  Brachial  Plexus  of  Nerves  and 
Branches  of  Ann.  1, 1,  The  Scalenus  Anticus  Mus- 
cle, in  front  of  which  are  the  Roots  of  the  Plexus. 

2,  2,  The  Median  Nerve.  3,  The  Ulnar  Nerve.  4,  Nerves  of  Front  of  Fore- Arm. 

The  Branch  to  the  Biceps  Muscle.  5,  The  Nerves  Median  Nerve.  2,  Anterior  Branch 

of  Wrisberg.  C,  Tlie  Phrenic  Nerve  from  the  of  Musculo-Spiral  or  Radial  Nerve. 

Third  and  Fourth  Cervical.  8,  Ulnar  Nerve.  4,  Division  of  Me- 

dian Nerve  in  the  Palm  to  the 
Thumb,  First,  Second,  and  Radial  Side  of  Third  Finger.  5,  Division  of  Ulnar 
Nerve  to  Ulnar  Side  of  Third  and  both  Sides  of  Fourth  Finger. 


COO.  What  nerves  go  to  make  up  the  cervical  and  brachial  plexus? 


AND  PHYSIOLOGY. 


335 


four  lower  cervical  and  upper  dorsal  nerves,  and  they  give  off 
their  branches  to  the  upper  part  of  the  body.  The  lumbar 
plexus  is  made  up  of  the  last  dorsal  nerve  and  the  five  lumbar 
nerves  ; and  the  sacral  plexus  of  a branch  of  the  last  lumbar 
and  the  upper  sacral  nerves.  These  supply  the  portions  of 
the  body  below  the  loins,  and  the  superficial  parts  of  the  body 
between  the  loins  and  upper  part  of  the  chest. 


Fig.  323. 


A View  of  the  Branches  of  the  Ischiati# 
Plexus  to  the  Hip  and  Back  of  the  Thigh. 
1,  1,  Posterior  Sacral  Nerves.  2,  Nervi 
Glutei.  3,  The  Internal  Pudic  Nerve 
(Nervus  Pudendalis  Longus  Superior).  4, 
The  Lesser  Ischiatic  Nerve,  giving  off  the 
Perineal  Cutaneous  (Pudendalis  Longus 
Inferior),  and  5,  The  Eainus  Femoralis 
Cutaneous  Posterior.  The  reference  to  the 
Great  Ischiatic  has  been  omitted.  It  is 
seen  to  the  right  of  3. 


and  Branches.  1,  Place  of  emergence 
Division  of  tho  Nerve  into  Branches. 
Branches  of  Obturator  Nerve. 


Fig.  324. 


A View  of  the  Anterior  Crural  Nerve 
of  the  Nerve  under  Poupart’s  Ligament.  2, 
3,  Femoral  Artery.  4,  Femoral  Vein.  5, 


6,  Nervus  Saphenus. 


Describe  the  lumbar  and  sacral  plexus. 

15 


. ^ 


336  HITCHCOCK’S  ANATOMY 

601.  Direction  of  the  Nerves. — The  largest  and  most  im- 
portant nerves  follow  the  same  general  direction  as  the  larger 
blood-vessels,  and  generally  are  in  close  proximity  to  them. 

602.  Motor  Nerves — Mode  of  Termination — Pacinian 
Corpuscles. — The  nerve  fibers  which  go  from  the  anterior 
columns  of  the  spinal  cord  terminate  in  the  fleshy  portions  of 
the  muscles,  because  they  are  the  motor  nerves,  or  those  ex- 


FiGr.  325. 


Pig.  326 


A View  of  the  Termination  of 
the  Posterior  Tibial  Nerve  in  the 
Sole  of  the  Foot.  1,  Inside  of  the 
Foot.  2,  Outer  Side.  8,  Heel.  4, 

Internal  Plantar  Nerve.  5,  Exter- 
nal Plantar  Nerve.  6,  Branch  to 
Flexor  Brevis.  7,  Branch  to  Out- 
side of  Little  Toe.  8,  Branch  to 

Hjtace  between  Fourth  and  Fifth  Toes.  9,  9,  9,  Digital  Branches  to  rernainin; 
Spaces.  10,  Branch  to  Internal  Side  of  Great  Toe. 


Pacinian  Corpuscles.  A,  Single  Corpuscle 
highly  Magnified,  a,  Its  Peduncle.  5,  Its  Nerve 
Fiber,  c,  Outer  Layers,  and  d.  Inner  Layers  of 
the  Capsule,  e,  Nerve  Fibers,  and  /,  Its  Subdi- 
vision and  Termination.  B,  Portion  of  Digital 
Nerves,  with  Pacinian  Corpuscles  attached. 


001.  Give  the  general  direction  of  the  nerves  through  the  body.  G02.  Where  do  the 
motor  nerves  terminate? 


AND  PHYSIOLOGY.  8o7 

citing  motion.  Those  from  the  posterior  columns  spread 
through  the  surface  of  the  body,  giving  sensation  to  the  skin. 
The  mode,  however,  in  which  they  terminate  is  not  always  the 
same.  As  far  as  at  present  is  known,  they  seldom  terminate 
in  a free  or  single  extremity,  but  in  loops,  returning  into 
themselves,  or  joining  with  other  fibers.  And  it  is  an  an- 
atomical fact  that  the  nerve  tubes  do  not  anastomose  one 
with  the  other,  as  is  the  case  among  the  blood-vessels ; but 
each  tube  discharges  its  own  duty,  and  not  that  of  another 
under  any  circumstances.  In  the  skin  of  the  hand  and 
foot  they  terminate  in  minute  oval  bodies  from  the  rlith  to 
the  TTo^b  of  an  inch  in  length,  and  from  one  twenty-sixth  to 
one  twentieth  of  an  inch  in  breadth,  called  Pacinian  Cor- 
puscles (from  Pacini,  their  discoverer),  and  are  attached  to 
the  branches  and  extremities  of  the  nerves  very  much  in  the 
same  manner  as  some  kinds  of  fruit  are  attached  to  their 
boughs.  (Pig-  326.)  Of  these,  there  are  about  six  hundred 
in  the  hand  and  a somewhat  smaller  number  in  the  foot.  They 
are  composed  of  connective  or  areolar  tissue  in  from  twenty 
to  sixty  bands,  with  interspaces  containing  a serous  fluid,  and 
are  attached  to  their  nervous  twig  by  a rounded  peduncle. 
The  function  of  these  bodies  is  entirely  unknown. 

603.  Sympathetic  System  — Its  Size  — Connection 
with  Spinal  Nerves — Destination  of  its  Branches. — 
Besides  the  cerebro-spinal  center,  there  is  another  organi- 
zation of  nervous  tissue  which  is  called  the  Sympathetic 
Nerve,  or  Ganglionic  System,  and  is  to  be  regarded  as  an 
appendage  of  the  spinal  nerves.  It  is  of  very  limited  size, 
consisting  of  mere  reddish  threads  of  nervous  matter  and  oval 
bodies  called  ganglia,  never  so  large  as  peas.  These  ganglia 
and  nerves  extend  along  each  side  of  the  spinal  column  from 


State  the  inanncr  in  which  they  terminate.  Give  a description  of  the  Pacinian  cor- 
puscles. 603.  What  is  said  of  the  structure  of  the  sympathetic  system  ? 


338 


II  T T C It  C O C K ’ S ANATOMY 


Fio.  327. 


tlio  atlas  to  tlic  coccyx, 

communicating  with  all 
the  spinal  nerves  hy  two 
small  fibers  (see  Fig. 

328),  and  giving  branches 
to  all  the  internal  organs 
and  viscera.  Branches 

and  ganglia  are  also 
found  between  the  bones 
of  the  cranium  and  the 
face.  The  branches 

which  are  given  olf  to  the 
internal  organs  accom- 
pany the  arteries  to  the 
same,  forming  a net- work 

Great  Sympatlietic  Nerve.  1, 
Plexus  on  the  Carotid  Artery  in  the 
Carotid  Foramen.  2,  Sixth  Nerve 
(Motor  Externus).  3,  First  Branch 
of  the  Fifth,  or  Ophthalmic  Nerve. 
4,  A Branch  on  the  Septum  Narium 
going  to  the  Incisive  Foramen.  5, 
Recurrent  Branch,  or  Vidian  Nerve 
dividing  into  the  Carotid  and  Petro- 
sal Branches.  6,  Posterior  Palatine 
Branches.  7,  Lingual  Nerve  joined 
by  the  Chorda  Tympani.  8,  Portio 
Dura  of  the  Seventh  Pair.  9,  Supe- 
rior Cervical  Ganglion.  10,  Middle 
Cervical  Ganglion.  11,  Inferior  Cer- 
vical Ganglion.  12,  Boots  of  the 
Great  Splanchnic  Nerve  arising  from 
the  Dorsal  Ganglia.  13,  Lesser 
Splanchnic  Nerve.  14,  Eenal  Plexus. 
15,  Solar  Plexus.  16,  Mesenteric 
Plexus.  17,  Lumbar  Ganglia.  13. 
Sacral  Ganglia.  19,  Vesical  Plexus. 
20,  Rectal  Plexus.  21,  Lumbar 
Plexus  (Cerebro-Spinal).  22,  Rec- 
tum. 23,  Bladder.  24,  Pubis.  25, 
Crest  of  the  Ilium.  26,  Kidney.  27, 
Aorta.  28,  Diaphragm.  29,  Heart. 
80,  Larynx.  31,  Submaxillary  Gland. 
32.  Incisor  Teeth.  33,  Nasal  Sep- 


tum. 3i,  Globe  of  the  Eye.  35,  36,  Cavity  of  the  Cranium. 


Where  does  it  give  Its  branches? 


AND  PHYSIOLOGY. 


339 


Fig.  328. 


c,  c,  Anterior  Fissure  of  the  Spinal  Cord,  a,  Anterior  Root,  j),  Posterior  Root,  with 
its  Ganglion,  a',  Anterior  Branch,  p',  Posterior  Branch,  s,  Sympathetic,  e.  Its 
Double  Junction  with  the  Anterior  Branch  of  the  Spinal  Nerve  by  a White  and  Gray 
Filament. 


of  communication  around  the  vessels.  And  as  all  the  inter- 
nal organs,  especially  those  called  vital,  are  supplied  with  this 
nerve,  and  not  directly  from  the  cerehro-spinal  center,  it  is 
hence  called  a nerve  of  organic  life. 

604.  Sympathetic  Ganglia. — Each  of  these  ganglia  may 
be  considered  as  a nervous  center  sending  forth  strands  in 
three  directions ; 1st,  to  join  the  spinal  nerves  in  their  dis- 
tribution ; 2d,  to  the  spinal  cord  itself ; 3d,  to  the  next  sym- 
pathetic ganglion  above. 


604.  What  may  each  of  these  ganglia  bo  considered  as  ? 


340 


HITCHCOCK’S  ANATOMY 


605.  Groups  of  Sympathetic  Ganglia.— These  ganglia 
are  grouped  together  according  to  the  locality,  to  which  their 
branches  are  distributed.  Thus  we  have  the  Cranial  ganglia, 
Cervical  ganglia,  Thoracic  ganglia.  Lumbar  ganglia,  and 
Sacral  ganglia.  Besides  these  there  are  several  large  plex- 
uses which  have  received  distinct  names,  although  a great 
number  of  small  ones  have  not  received  any  names.  Of  the 
most  important  ones  we  may  name  the  Pharyngeal,  in  the 
immediate  vicinity  of  the  Pharynx,  the  Cardiac  lying  upon 
the  heart,  and  the  Solar,  between  the  liver  and  stomach,  or, 
as  is  more  commonly  known,  the  pit  of  the  stomach. 

606.  The  Solar  Plexus. — The  Solar  Plexus  seems  to  be, 
as  its  name  implies,  a sun  or  center  for  nervous  power  to  the 
intestines,  since  branches  from  this  plexus  accompany  the  ar- 
teries to  the  vital  organs,  where  they  subdivide  again  and 
again,  and  enter  their  coats  and  substance. 


FUNCTIONS  OF  THE  NERVOUS  SYSTEM 

607.  The  functions  of  the  Nervous  System  are  the  most 
important  and  delicate  of  any  in  the  body.  1.  The  Brain 
affords  a seat  and  center  for  life  and  intellect.  2.  The  nerves 
are  inlets  for  all  the  senses  to  the  sensorium  or  seat  of  sensa- 
tion. 3.  They  are  the  medium  of  all  the  movements  of  the 
body,  voluntary  and  involuntary.  4.  They  establish  and 
maintain  a sympathy  between  all  the  parts  of  the  body,  and 
equalize  all  the  vital  forces.  5.  They  preside  over  the  in- 
voluntary functions,  such  as  the  circulation  of  the  blood,  di- 
gestion, respiration,  and  reflex  actions. 

608.  Inlcllect  and  Will  located  in  the  Brain.— 
Voluntary  Movements  dependent  on  the  Brain. — 
The  whole  Brain  not  essential.  — The  Intellect  and 


O'lr*.  How  arc  the  syinjmtlictlo  {ranglla  {^rouped  together?  What  is  said  of  the  syrn- 
j)at,hctlc  i)lexu8CH?  (i(Mh  Describe  the  solar  plexus,  607.  What  are  the  five  principal  func- 
tions of  the  nervous  system  ? 


AND  PHYSIOLOGY. 


341 


Will  evidently  reside  in  the  brain  (cerebrum),  and  re- 
quire that  this  organ  should  be  in  a healthy  state,  since, 
if  any  disease  affects  its  whole  substance,  their  power  is 
destroyed.  Voluntary  muscular  movements  depend  on  a 
sound  and  healthy  brain,  although  reflex  movements,  and  the 
motion  necessary  to  sustain  animal  life,  are  often  carried 
on  in  some  animals  for  a considerable  time,  when  they  are 
born  without  a brain.  But  the  whole  brain  does  not  seem  to 
be  absolutely  essential  to  life  and  mental  operations,  for  many 
instances  are  mentioned,  where  a considerable  portion  of  the 
brain  has  been  removed  by  accident,  such  as  a bullet  or  iron 
bar  being  shot  through  the  head  followed  by  a discharge 
of  nervous  matter : and  yet  the  persons  have  lived  for 
years  subsequent  to  the  accident  in  as  sound  a condition  as 
ever. 

608a.  Necessity  of  two  Cerebral  Hemispheres —One 
may  be  injured,  and  not  the  other. — The  reason  of  the 
division  of  the  brain  into  lobes  or  hemispheres  is  not  so  easily 
understood.  Perhaps  it  may  be  that  so  large  an  organ  of  so 
soft  a substance  could  not  easily  sustain  its  own  weight,  es- 
pecially when  reclined  on  one  side,  and  at  the  same  time 
properly  perform  its  functions.  A more  probable  reason, 
however,  is  this.  It  is  a well-known  fact,  that  one  of  the 
hemispheres  may  be  diseased  or  injured,  so  as  to  perform  its 
functions  imperfectly,  and  yet  the  other  hemisphere  be  in  its 
ordinary  healthy  state.  Also  one  hemisphere  may  be  so 
much  afiected,  that  the  opposite  side  of  the  whole  body  is 
paralyzed  in  motion  or  sensation,  or  both.  It  then  seems 
reasonable  to  suppose,  that,  since  the  brain  would  be  so  liable 
to  injuries,  it  was  made  in  two  portions,  so  as  to  prevent  the 
entire  destruction  of  life  by  an  injury  to  one  of  the  hemi- 
spheres. 


608.  Where  are  the  intellect  and  the  will  located  ? What  movements  depend  on  the 
brain  ? Is  the  whole  brain  absolutely  essential  for  intellection  ? 608  ii.  Why  are  there 
probably  two  hemispheres  to  the  brain? 


342 


HITCHCOCK’S  anatomy 


609.  To  secure  Precision  in  all  Voluntary  Actions. 
— In  Draper’s  Physiology  is  found  another  hypothesis  for  the 
division  of  the  brain  into  two  parts : this  is  to  secure  precision 
in  the  efforts  of  the  intellect  and  will.  For  there  is  no 
doubt/^  he  says,  ^‘that  the  hemispheres  have  not  only  the 
power  of  acting  separately,  but  also  conjointly  ; thus  there  is 
no  student  but  must  have  observed,  when  busily  engaged  in 
reading,  that  his  mind  will  wander  off  to  other  things,  though 
he  may  mechanically  cast  his  eye  over  page  after  page ; and 
the  same  may  occur  in  listening  to  a lecture  or  sermon.  But 
though  the  insane  man  may  indulge  in  two  synchronous  trains 
of  thought,  he  never  indulges,  in  three,  for  the  simple  reason 
that  he  has  not  three  hemispheres  to  do  it  with,  the  same  re- 
mark applying  to  the  sane  man  in  the  accidental  wandering 
of  his  thoughts.’’ 

610.  Tlioiiglit,  Memory,  and  the  Reasoning  Powers 
require  a Sound  Brain. — As  already  mentioned,  the  brain 
is  not  the  seat  of  motive  power  : this  does  not  originate  here, 
although  voluntary  movements  are  controlled  by  it.  But 
automatic  or  reflex  movements,  such  as  the  twitching  of  the 
muscles  of  the  leg  and  foot,  when  the  sole  of  the  foot  is 
tickled  with  some  slightly  irritating  substance,  are  entirely 
beyond  the  control  of  the  cerebrum  or  will,  since  they  take 
place  nearly  as  well  in  a person  who  is  asleep  or  stunned  by 
a blow,  or  even  when  the  nerves  of  sensation  and  motion  are 
paralyzed.  Thought,  memory,  reasoning,  and  all  the  intel- 
lectual states  demand  a healthy  and  a sound  brain  for  their 
perfect  action,  while  the  ordinary  muscular  movements  and 
the  functions  of  respiration,  circulation,  and  digestion,  are 
dependent  upon  the  Spinal  Cord,  Sympathetic  Nerve,  and 
Cerebellum. 

611.  Definition  of  Sleep. — Need  of  Sleep.  — Sleep, 
‘Hired  nature’s  sweet  restorer,”  is  a state  of  the  body,  in 

COI).  can  two  lu‘inisi>lierc8  scciiro  a precision  in  voluntary  actions  ? 610.  Aro 

reflex  movements  under  tlio  control  of  tho  bruin?  What  powers  of  mind  aro  dei)endent 
on  tho  cerebrum  ? 


AND  PHYSIOLOGY. 


843 


■which  there  is  a more  or  less  perfect  suspension  of  the  activ- 
ity of  the  brain.  The  functions  of  digestion,  secretion,  and 
respiration,  proceed  during  the  soundest  sleep,  though  with 
less  activity  than  during  the  wakeful  state.  In  many  cases, 
however,  the  functions  of  the  brain  do  not  entirely  cease,  as 
is  seen  in  the  phenomena  of  dreaming,  where  the  brain  seems 
to  be  actively  at  work,  but  the  senses  and  animal  functions 
are  quiescent.  Sleep  is  demanded  by  all  animals  to  procure 
rest  to  the  different  organs  of  the  body,  and  in  health  it  comes 
to  all,  though  in  different  degrees  of  soundness,  but  generally 
the  greater  the  exhaustion,  the  more  complete  the  sleep. 

612.  Periodical  Tendency  of  Sleep— The  Will  can 
for  some  Time  overcome  Sleep. — The  tendency  to  sleep 
is  periodical.  All  persons  feel  an  inclination  to  sleep  during 
some  portion  of  the  twenty-four  hours,  and  during  the  night, 
if  health  be  good  and  nature  not  perverted.  Some  strong 
intellectual  effort,  however,  or  some  powerful  emotion,  will 
overcome  drowsiness  for  a long  time,  as  in  the  case  of  the 
student  working  out  a difficult  problem,  or  a mother  watching 
her  sick  child.  But  when  the  problem  is  mastered,  and  the 
child  has  safely  passed  the  crisis,  sleep  comes  on  with  irresist- 
ible force.  Cases  occur  constantly  to  show  that  the  brain 
must  have  its  repose  in  spite  of  intellectual  effort  or  danger. 
It  is  related  that  boys  wearied  out  with  continued  labor  in  the 
battle  of  the  Nile,  slept  during  a part  of  the  action,  and  in 
another  naval  engagement,  a captain  slept  two  hours  within  a 
yard  of  his  largest  gun,  which  was  kept  in  action  during  the 
whole  time.  Indians  at  the  stake  of  torture  will  sleep  on  the 
least  remission  of  agony,  but  awake  as  soon  as  it  is  renewed 
again.  And  we  learn  that  a most  barbarous  punishment  is 
still  practiced  in  China,  that  of  keeping  a victim  awake  until 
he  dies  of  sheer  exhaustion.  The  distress  of  it  is  said  to  be 
terrible. 

611.  What  is  sleep?  What  powers  are  inactive  (luring  sleep,  and  what  processes  are 
carried  on  during  it?  What  is  sleep  necessary  for?  612.  State  the  fact  of  a periodical 
tendency  to  sleep.  Can  the  will  overcome  sleep?  For  how  long  a time  can  it  do  it  ? 
Eelate  the  facts  mentioned. 

15* 


344 


HITCHCOCK’S  ANATOMY 


613.  Inducements  to  Sleep— Sleep  sometimes  under 
the  Control  of  the  Will. — Ordinarily  darkness  and  si- 
lence promote  sleep ; but  if  a person  once  becomes  habituated 
to  noise  during  slumber — if  it  be  a continuous  one — he  can 
not  sleep  well  without  it.  Thus  persons  living  in  the  vicinity 
of  forges  and  noisy  mills  can  not  readily  sleep  elsewhere.  And 
a monotonous  repetition  of  sounds  is  a most  favorable  provo- 
cative to  sleep,  the  cause  of  which  is  that  other  impressions 
can  not  so  readily  be  made  on  the  mind,  and  thus  the  sleeper 
is  less  easily  roused.  A dull  reader  on  a dull  subject  has  a 
most  ready  eflFect  in  producing  sleep,  as  well  as  the  sound  of 
a distant  waterfall,  or  the  rustling  of  leaves  in  a forest.  Rub- 
bing many  parts  of  the  skin,  or  combing  the  hair  by  another 
person,  'will  often  cause  drowsiness,  and  sometimes  sleep. 
Again  a person  can  sometimes  put  himself  to  sleep,  if  restless, 
by  a monotonous  intellectual  effort,  such  as  the  rehearsal  of  a 
Latin  paradigm,  or  counting  the  rain-drops,  as  they  fall  from 
the  eave  trough  into  the  spout. 

614.  Effect  of  Habit  on  Sleep. — The  effect  of  habit  is 
powerful  in  producing  sleep.  Let  one  be  accustomed  to  retire 
early — in  accordance  with  nature — and  sleepiness  comes  at 
the  usual  hour  for  retiring ; but  if  a person  for  a series  of 
years  is  in  the  habit  of  sleeping  the  latter  part  of  the  night 
and  early  in  the  morning,  it  is  almost  impossible  for  him  to 
sleep  early  in  the  night.  Those  persons  who,  like  sailors, 
soldiers,  and  watchers,  are  obliged  to  catch  sleep  when  they 
call  get  it,  and  then  only  in  small  amounts  at  a time,  sleep 
with  but  little  difficulty  when  the  opportunity  presents  itself. 
Captain  Barclay,  who  walked  one  thousand  miles  in  as  many 
consecutive  hours,  had  such  a*  power  over  himself,  that  he  was 
asleep  the  moment  he  lay  down.  Some  physicians  have  the 
same  power. 

CIO.  What  arc  tho  common  inducements  to  sleep?  Do  any  persons  ever  require  a 
noise,  in  order  to  sleep  soundly  ? What  effect  does  rubbing  or  chafing  certain  parts  of 
tho  body  have  upon  sleep?  Can  sleep  over  be  brought  about  by  an  action  of  the  will? 
How  ? 614.  What  effect  has  habit  upon  producing  sleep  ? Mention  the  case  of  Captain 
liarclay. 


AND  PHYSIOLOGY. 


345 


615.  Preventives  of  Sleep. — Any  unusual  noise  or  place 
of  sleeping  will  prevent  or  disturb  the  sleep  of  many  persons. 
Thus  the  singing  of  a mosquito  keeps  many  a man  awake  a 
long  time.  But  if  a noise  be  repeated  often,  it  will  have 
no  effect  of  this  kind.  The  college  Freshman  for  the  few  first 
mornings  is  readily  awaked  by  the  first  stroke  of  the  early 
prayer-bell,  but  in  a short  time  it  has  no  effect  w^hatever. 

A gentleman  who  had  taken  his  passage  on  board  a man  of 
war,  was  aroused  on  the  first  morning  by  the  report  of  the 
morning  gun,  which  chanced  to  be  fired  just  above  his  head ; 
the  shock  was  so  violent  as  to  cause  him  to  jump  out  of  bed. 
On  the  second  morning  he  was  again  awakened,  but  this  time 
he  merely  started  and  sat  up  in  bed ; on  the  third  morning 
the  report  had  simply  the  effect  of  causing  him  to  open  his 
eyes  for  a moment  and  turn  in  his  bed  ; on  the  fourth  morn- 
ing it  ceased  to  affect  him  at  all,  and  his  slumbers  continued 
to  be  undisturbed  so  long  as  he  remained  on  board.” 

616.  An  Absence  of  Accustomed  Sounds  prevents 
Sleep. — The  reverse  of  this  sometimes  happens,  if  there  be  a 
cessation  of  monotonous  and  unaccustomed  sound,  by  which 
sleep  was  induced.  Thus  a person  who  has  been  read  or 
preached  to  sleep,  will  awake  if  the  reader  or  preacher  pause 
or  stop,  before  any  disturbance  is  made,  and  a person  asleep 
in  a railway  train,  will  often  awake  on  the  stopping,  or  even 
on  the  slackening  of  the  train. 

617.  Amount  of  Sleep. — The  amount  of  sleep  necessary 
for  man,  varies  exceedingly,  being  affected  by  the  conditions 
of  age,  temperament,  habit,  and  exhaustion.  Infants  and 
very  old  people  sleep  the  most.  The  former  require  it  that 
the  constructive  process  may  go  on  as  uninterruptedly  as 
possible,  and  they  generally  sleep  three  fourths  of  the  time. 
The  latter  need  a large  amount  of  sleep,  because  the  vital 
energies  are  so  feeble. 


615.  What  -will  often  easily  prevent  sleep  ? Instance  the  college  Freshman  and  the 
gentleman  on  the  man  of  war.  616.  How  does  an  absence  of  accustomed  sounds  affect 
sleep  ? 617.  What  amount  of  sleep  is  necessary  ? What  ages  sleep  the  most  ? 


346 


HITCHCOCK’S  ANATOMY 


618.  A lymphatic  Temperament  a Sleepy  one, — Persons 
of  a lymphatic  temperament,  those  who  are  seldom  excited, 
sleep  more  than  those  of  a nervous  temperament,  who  are 
always  rapid  and  quick  in  their  movements.  The  former  live 
slowly,  and  but  comparatively  little  waste  is  going  on,  and 
consequently  the  brain  is  all  the  time  nearer  to  sleep  than  in 
the  latter  class,  whose  brain,  when  awake,  is  very  active,  and 
when  asleep,  is  asleep  very  soundly. 

619.  Effect  of  Habit  on  the  Amount  of  Slcep.~Rc- 
markable  Cases. — The  amount  of  sleep  is  greatly  modified 
by  habit,  and  often  the  briefest  sleepers  have  been  men  of  the 
greatest  activity.  If  a person  acquire  the  habit  of  sleeping 
but  little,  he  must  sleep  very  profoundly,  so  that  what  is  lost 
in  quantity,  is  made  up  in  intensity.  The  habit  of  taking 
but  little  sleep,  however,  is  not  a sure  indication  that  a proper 
amount  of  it  has  been  secured.  Frederic  the  Great,  and 
J ohn  Hunter  slept  but  five  hours  out  of  the  twenty-four ; and 
General  Elliot,  engaged  in  the  defense  of  Gibraltar,  and  Na- 
poleon, often  slept  but  four  hours  out  of  the  twenty-four. 

•The  general  rule,  however,  seems  to  be  that  man  should 
take  from  six  to  eight  hours  of  the  twenty-four,  for  uninter- 
rupted slumber.  Women  in  general  seem  to  require  rather 
more. 

620.  Mode  of  Access  of  Sleep. — To  some  sleep  comes  on 
instantly  when  the  will  determines  upon  it,  but  to  others  it  is 
a gradual  and  tedious  process,  especially  in  ill  health,  or  an 
excited  mental  state.  Many  physicians  drop  asleep  as  soon  as 
the  head  touches  the  pillow,  and  are  aroused  by  no  ordinary 
sound,  such  as  the  tread  of  another  person  in  the  room,  or 
the  shutting  of  a door,  but  wake  as  soon  as  the  night-bell  is 
rung.  Sir  E.  Codrington,  when  a young  man  in  the  naval 
service,  was  very  active  at  one  time  in  looking  out  for  signals. 


CIS.  Wliat  aro  tho  sleepy  ternporamonts ? What  the  wide-awake  ones ? G19.  How* 
does  liabit  alFect  tho  amount  of  sleep  ? State  some  remarkable  cases.  What  is  an  average 
amount  of  sleep  for  men  ? How  muoli  forwomon?  G20.  How  does  sleep  come  on> 
Give  oxamplea. 


AND  PHYSIOLOGY. 


347 


and  was  employed  during  his  waking  hours  in  this  business. 
Hence  his  sleep  was  very  solid,  and  he  was  roused  by  no  or- 
dinary sound,  but  his  comrades  amused  themselves  by  whis- 
pering the  word  ^^signaP’  in  his  ear,  when  he  was  at  once 
aroused  and  fit  for  duty. 

621.  Functions  of  the  Cerebellum. — The  Cerebellum 
does  not  seem  to  be  in  any  manner  directly  connected  with 
the  phenomena  of  mind.  But  it  seems  designed  simply  for 
the  purpose  of  combining  the  actions  of  different  muscles,  or 
presides  over  the  coordination  of  voluntary  muscular  move- 
ments, as  in  walking,  speaking,  and  similar  actions  requiring 
several  sets  of  muscles  to  be  used  at  the  same  instant.  Ac- 
cordingly in  animals,  which  possess  the  greatest  variety  of 
movements,  we  find  the  largest  cerebellum. 

622.  Effects  when  Removed  from  Animals. — The  Con- 
trolling Power  of  Muscular  Motions. — ^When  this  organ 
has  been  removed  from  some  of  the  lower  animals,  it  was  found 
that  they  could  not  control  their  movements.  When  laid 
down  they  could  not  recover  their  erect  posture,  and  when 
threatened  with  a blow,  they  in  vain  endeavored  to  avoid  it. 
Another  phenomenon  attending  a wound,  or  removal  of  both 
sides  of  the  cerebellum,  was  the  motion  of  the  animal  in  a 
backward  direction,  and  the  rolling  firom  side  to  side  on  the 
longitudinal  axis  of  the  body,  and  keeping  up  this  motion 
uninterruptedly,  for  several  hours,  at  the  rate  of  sixty  revolu- 
tions per  minute.  In  some  men  who  have  been  afflicted  with 
a disease  of  this  organ,  an  unsteadiness  of  gait  has  been  ob- 
served, which  gives  additional  strength  to  the  belief  that  the 
Cerebellum  is  the  regulator  of  muscular  movemeuts. 

623.  Functions  ot  the  Medulla  Oblongata.— The  Me- 
dulla Oblongata  seems  to  have  for  its  function  the  sending  of 
nervous  power  to  the  muscles  of  respiration  and  swallowing. 


621.  Does  the  cerebellum  control  the  phenomena  of  mind?  What  are  its  functions’ 
622.  What  effects  does  its  removal  cause  in  animals  ? How  does  a disease  of  it  affect 
men  ? 623.  What  operations  are  controlled  by  the  medulla  oblongata  ? 


348 


niTc  II  cock’s  anatomy 


or,  in  other  words,  respiration  and  deglutition  arc  controlled 
and  performed  by  the  medulla  oblongata. 

624.  Function  of  the  Cerebral  Ganjilia. — The  scries  of 
Ganglia,  Corpora  striata,  Thalami  optici,  etc.,  are  regarded  by 
Dr.  Carpenter  as  the  true  sensorium  in  man,  and  this  is  one 
of  the  most  important  facts  established  with  regard  to  the 
nervous  system.  A prominent  reason  for  the  belief,  that  the 
brain  is  simply  superadded  to  them,  is  seen  in  many  instances 
of  children  born  without  a brain,  but  with  the  sensory  ganglia 
present,  where  the  functions  of  animal  life  have  been  carried 
on  for  a considerable  length  of  time. 

625.  Functions  of  the  Spinal  Cord. — The  functions  of 
the  Spinal  Cord  are  considered  in  a double  aspect : First,  as 
the  means  of  communication  between  the  roots  of  the  spinal 
nerves,  and  those  parts  of  the  nervous  system  within  the 
cranium,  and  second,  as  a center  of  nervous  power  to  pro- 
duce reflex  movements  when  an  impression  is  made  upon  this 
cord. 

626.  Function  of  Sympathetic  Nerve.— The  Sym- 
pathetic Nerve  ‘4n  its  offices  is  a motor  nerve  to  many  of  the 
internal  viscera  of  the  body,  the  heart  and  the  intestinal  canal 
especially ; it  is  also  a sensitive  nerve  to  these  parts,  and  it 
presides  over  the  action  of  the  blood-vessels  of  these  as  well 
as  of  the  other  parts,  wffiere  it  is  distributed,  as  of  the  head 
and  neck,  and  likewise  of  all  the  principal  glands  of  the 
body.’’ 

627.  Organic  Functions  depend  on  the  Spinal  Cord.— 
Effect  of  Pressure  on  this  Cord. — Almost  all  the  func- 
tions of  organic  life,  such  as  breathing,  digestion,  and  circu- 
lation, are  greatly  influenced  by  the  condition  of  the  spinal 
cord,  and  especially  in  its  connection  with  the  sympathetic 
nerve,  although  the  brain  has  some  controlling  power.  Yet 


0*24.  liy  what  set  of  bodies  are  the  principal  functions  of  animal  life  carried  on?  625. 
What  arc  the  functions  of  tlic  spinal  c<u*d  ? 626.  Give  the  use  of  the  sympathetic  nerve. 
027.  Upon  what  portions  of  the  nervous  system  do  organic  function'^  depend? 


AKD  PHYSIOLOGY. 


349 


■when  we  are  asleep,  or  the  brain  is  stunned  by  a blow,  the 
organic  functions  are  carried  on  as  in  the  state  of  the  activity 
of  the  brain,  though  with  far  less  energy.  And  in  the  case 
already  mentioned  of  animals  born  without  a brain,  life  (or- 
ganic) may  be  sustained  for  a considerable  time  merely  by  the 
functions  of  the  spinal  cord.  If  this  cord  be  severed  near  the 
head,  or  even  if  it  be  compressed,  life  soon  ceases.  This  is 
the  manner  in  which  death  ensues  by  hanging,  or  breaking  the 
neck  as  it  is  termed  ; where  one  vertebra  is  slipped  from  its 
place  (put  out  of  joint),  so  that  by  the  unequal  contraction 
of  the  muscles  such  a pressure  is  made  on  the  cord  that  life 
speedily  becomes  extinct.  And  if  this  cord  is  compressed  in 
any  portion,  sensibility  and  the  power  of  motion  in  muscles 
supplied  by  the  part  below  the  point  of  compression  are  de- 
stroyed ; and  if  the  pressure  be  long  continued,  or  the  cord 
divided,  its  vitality  is  for  ever  destroyed,  although  the  parts 
above  it  are  only  indirectly  affected. 

628.  Sensation  Exists  Previonsly  to  Motion— Centri- 
petal and  Centrifugal  Fibers— Rate  of  Movement  throiigli 
the  Nerves, — From  the  fact  that  one  portion  of  each  nerve  is 
designed  for  sensation,  and  the  other  for  motion,  it  is  probable 
that  sensation  must  exist  previous  to  the  motion  of  the  part. 
Thus,  for  example,  if  the  hand  be  brought  in  contact  with  any 
substance  without  any  previous  knowledge  of  its  presence,  no 
matter  how  soon  the  hand  may  seem  to  grasp  it,  yet  the  in- 
terval must  have  been  long  enough  for  the  sensation  contact 
to  have  passed  from  the  hand  to  the  brain,  and  the  will  to  de- 
termine upon  the  condition  of  the  muscles,  and  the  order  to 
pass  down  through  the  white  fibers  to  the  hand  again  before 
the  grasping  can  take  place.  Or  the  same  thing  may  taka 
place  on  receiving  a shock,  or  series  of  shocks,  from  a gal- 
vanic battery,  the  contractions  in  this  case  being  an  instance 
of  involuntary  or  reflex  movement.  And  although  this  fact 


What  is  the  effect  of  pressure  upon  or  division  of  the  spinal  cord  ? 628.  What  tVo 
functions  exist  in  each  nerve  ? Which  exists  first,  motion  or  sensation  ? 


350 


HITCHCOCK’S  ANATOMY 


seems  clearly  established,  that  one  portion  of  each  nerve  trans- 
mits the  sensation  to  the  brain,  called  the  centripetal  or  sen- 
sory, and  the  other  conveys  the  order  to  the  muscle,  called  the 
centrifugal  or  motor,  yet  no  anatomical  difference  can  be  de- 
tected between  the  different  fibers  of  the  nerve.  From  this 
fact  a German  physiologist  has  made  a series  of  curious  cal- 
culations, as  a result  of  which  he  concludes  that  nervous  in- 
fluence, such  as  the  will  to  move  a certain  muscle,  travels  at 
the  rate  of  195  feet  per  second. 

629.  Ganglia  Reservoirs  of  Power— It  has  been  sug- 
gested, and  with  reason,  that  the  ganglia,  abundant  as  they  are 
in  the  body,  act  as  reservoirs  of  nerve  force,  and  the  frequent 
commissures,  or  union  and  subsequent  divergence  of  nerve 
fibers,  is  to  draw  off  a part  of  the  influence  which  is  coming 
along  the  centripetal  fiber,  and  directing  it  into  a new  chan- 
nel. 

630.  Divisions  of  the  Cranial  Nerves.— The  cranial 
nerves  may  be  divided,  according  to  their  function,  into  three 
groups  : 

Special  Sense, 


Motion ^ 


Compound 

631.  The  olfactory  nerve  is  the  one  by  which  we  gain  the 
smell  of  odoriferous  substances,  as  they  are  brought  in  con- 
tact with  this  nerve  in  the  lining  membrane  of  the  nose. 

"What  aro  tlio  centripetal  and  what  the  centrifugal  fibers  of  the  nerves?  What  is  a 
probable  rate  at  which  the  intluonco  is  transmitted  through  the  nerves  to  and  from  the 
i>rain  ? 6‘29.  What  theory  lias  been  olTered  for  the  use  of  the  ganglia?  630.  What  thrcti 

groups  of  the  cervical  nerves  are  Loro  given?  631-640.  State  the  function  of  each  pair 
of  the  cranial  nerves. 


Olfactory. 

Optic. 

Auditory. 

Motores  Oculorum. 

Patheticus. 

Abducentes. 

Facial. 

Lingual. 

Trifacial. 

Glosso-Ph  aryngeaL 
Par  Yagum. 

Spinal  Accessory. 


AND  PHYSIOLOGY. 


351 


632.  The  optic  nerve,  as  expanded  in  the  retina,  is  the 
nerve  of  sight. 

633.  The  auditory  nerve  receives  the  vibrations  of  the  air, 
which  produce  sound. 

634.  The  motores  oculorum,  pathetici,  and  abducentes  are 
the  nerves  which  furnish  motive  power  to  the  eye-ball. 

635.  The  facial  nerve  is  distributed  to  the  muscles  of  the 
face,  and  is  the  one  that  aids  in  the  expressions  of  the  emo- 
tions and  will,  as  exhibited  in  the  countenance.  It  is  also  the 
channel  of  the  reflex  actions  in  respiration,  as  when  a person 
involuntarily  gasps  if  cold  water  be  dashed  in  the  face. 

636.  The  lingual  (hypoglossal)  nerve  is  necessary  for  the 
production  of  articulate  speech,  regulating  and  controlling  as 
it  does  the  muscles  of  the  tongue. 

637.  The  trifacial  nerve  administers  the  sense  of  touch  to 
the  surface  of  the  tongue,  and  aids  somewhat  in  the  sense  of 
taste.  One  branch  of  it  is  a muscular  branch.  Another  is 
sent  to  the  mucous  surface  of  the  eye,  and  if  it  be  cut  off  the 
eye  is  destroyed  by  suppuration. 

638.  The  glosso-pharyngeal  is  the  essential  nerve  of  taste, 
and  is  closely  connected  in  function  with  the  trifacial.  It 
seems  also  to  be  the  nerve  through  which  unpleasant  sensa- 
tions excited  in  the  mouth  are  conveyed  to  the  medulla  ob- 
longata so  as  to  excite  nausea  and  vomiting. 

639.  The  par  vagum  sends  nervous  power  to  the  heart- 
stomach,  lungs,  and  larynx,  as  well  as  conveys  to  the  brain 
any  disagreeable  sensations  excited  in  these  organs.  Conse- 
quently this  is  the  essential  nerve  of  digestion,  respiration, 
circulation,  and  opening  or  closure  of  the  glottis  under  ordi- 
nary circumstances. 

640.  The  spinal  accessory  seems  to  be  the  nerve  by  which 
the  regulation  of  the  muscles  essential  to  the  production  of 
voice  is  effected. 


352  HITCHCOCK’S  ANATOMY 

641.  Use  of  Spinal  Nerves. — The  use  of  the  Spinal 
Nerves  is  to  convey  impressions  made  at  the  surface  of  the 
body — including  the  extremities — to  the  brain,  and  to  trans- 
mit impulses  to  the  muscles  from  the  brain.  Both  of  these 
influences  are  transmitted  by  the  same  nerve  or  filament, 
though  in  opposite  directions.  From  carefully  conducted  ex- 
periments it  seems  quite  probable  that  the  “coarse  fibers’’ 
transmit  the  impulses  to  the  muscles,  and  are  called  afferent, 
while  the  fine  fibers  conduct  the  impressions  to  the  l)rain,  and 
are  called  efferent.  And  in  the  muscular  nerves  the  coarse 
fiber  is  proportioned  to  the  fine  as  10  : 3.eS,  while  in  the 
trunk,  as  it  issues  from  the  spinal  cord,  it  is  in  the  ratio  of 
10  : 11. 


IIYGIENTC  I TERENCES. 

642.  TIic  Nervous  System  not  easily  Diseased. — 1.  It 
is  a singular  fact  that  the  nervous  system,  so  delicate  in  its 
organization  and  mysterious  in  many  of  its  functions,  is  to 
so  small  an  extent  dependent  upon  any  particular  rules  for 
the  maintenance  of  its  health,  the  main  thing  necessary  for 
its  welfare  being  an  attendance  to  the  general  health  of  the 
body. 

643.  It  needs  Aetion, — 2.  The  nervous  system,  like  all 
other  parts  of  the  bod^  requires  action  for  its  health.  If  a 
person  has  nothing  upon  which  he  can  exert  his  nervous 
energy,  he  is  liable  to  disease ; and  no  class  of  people  are  so 
subject  to  nervous  diseases  as  the  wealthy,  who  are  obliged  to 
make  little  exertion  to  procure  the  necessaries  and  luxuries  of 
life.  Hence  we  infer  that  employment  of  some  kind  is  indis- 
pensable to  the  health  of  the  nervous  system. 

644.  Sleep  indispensable  to  its  llealtli. — 3.  This  system 


C41.  What  Is  tho  nso  of  tlio  spinal  norvos?  What  is  the  ditferenco  in  function  between 
the  coarse  and  tlio  flno  fibers?  012.  Is  tho  nervous  system  easily  alb'cted  by  serious  dis- 
ease ? 648.  What  is  tho  necessity  of  action  to  tho  nervous  system  ? 


AND  PHYSIOLOGY. 


S53 


requires  sound  sleep.  For  this  alone  can  return  to  the  brain 
its  expended  energies.  It  is  as  necessary  to  the  brain  as 
steam  to  the  locomotive.  And  no  person  can  enjoy  the  per- 
fection of  health  to  old  age,  who  does  not  gain  a due  supply 
of  sleep.  Hence  the  very  ambitious  student,  or  the  man  eager 
to  make  money,  whose  time,  energies  and  thoughts  are  so 
engrossed  that  he  can  not,  or  will  not,  find  time  to  sleep,  vio- 
lates one  of  nature’s  principal  laws,  and  sooner  or  later  will 
receive  the  penalty.  And,  according  to  insane  hospital  re- 
ports, one  of  the  principal  causes  of  insanity  is  put  down  to  a 
want  of  sleep. 

645.  Needs  Rest  and  Recreation. — 4.  The  mind  not  only 
needs  sleep,  but  also  recreation  or  an  occasional  change  of  its 
objects  of  thought.  Long-continued  trains  of  thought  are  to 
the  brain  what  working  one  set  of  muscles  incessantly  all  day 
is  to  them — complete  exhaustion.  He  then  that  would  last 
the  longest,  must  occasionally  turn  his  thoughts  from  his  or- 
dinary avocation  completely,  and  so  give  the  brain  rest.  This 
applies  to  every  one,  whether  he  is  tlm^business  man,  student, 
or  the  hard-working  farmer  (^;iBfechanic.  And  every  one 
also  needs  a vacation,  or  at  least  some  change  of  employment, 
once  or  twice  during  the  yeam^hen,  .for  a few  weeks  or  days, 
he  may  break  up  the  ordinary»utine  of  life. 

646.  Necessity  of  variousmbi^ts ^for  tol'di- 

vert  itself  with. — 5.  If  chan^&^fep-eation  be  so  ip^p^- 
tant  for  the  health,  how  necessary  tnS^&e  ^mind  should  Wive 
various  objects  on  which  to  employ  itself  from  daily 

duties.  How  pleasantly,  and  profitably,  for  instance,  can 
one  pass  his  leisure  hours,  if  he  will  but  cultivate  a taste 
for  music,  reading,  or  some  branch  of  natural  history,  as  for 
example  zoology,  botany,  mineralogy,  or  geology!  These 
pursuits  not  only  give  healthful  physical  recreation,  but  by 

644.  What  is  the  effect  of  a want  or  scarcity  of  sleep  ? What  is  often  a prominent 
cause  of  insanity  ? 645.  What  kind  of  rest  does  the  mind  need  besides  sleep?  Do  all 
employments  need  a vacation  ? 646.  Is  exercise,  that  is  taken  simply  for  exercise,  ever 
the  best  ? What  studies  combine  profit  as  well  as  recreation  and  exercise  ? 


354  HITCHCOCK’S  ANATOMY 

tlic  attractive  and  fascinating  objects  of  study  which  they 
offer,  they  divert  the  mind  from  the  ordinary  cares  and  trou- 
bles of  life,  and  also  exert  a healthful  moral  influence.  To 
literary  and  professional  men,  as  well  as  many  of  business 
engagements,  such  a source  of  recreation  and  improvement  is 
of  very  great  importance,  since  often  they  arc  not  interested 
in  many  of  the  recreations  and  pleasures  which  divert  the 
great  mass  of  society,  and  also  because  new  thoughts  and 
means  of  illustration  may  be  gained  from  them. 

647.  The  Brain  must  be  worked  Philosophically,  not 
Spasmodically. — 6.  The  brain  and  nervous  system  will  per- 
form more  labor,  if  w'orked  philosophically,  than  if  worked 
spasmodically.  That  is,  mental  and  corporeal  labor  performed 
regularly  and  steadily,  and  only  up  to  the  ordinary  power  of 
the  brain  and  nerves  to  sustain,  will  not  wear  away  the  ner- 
vous system  to  such  an  extent  as  if  it  be  performed  by  over- 
working for  a few  days  and  then  lying  idle. 

648.  Value  of  "dental  Abstraction.— 7.  As  a general  fact 
the  mind  acting  through  the  brain  can  not  successfully  work  in 
the  midst  of  noise  and  external  attractions.  But  by  practice 
many  can  engage  in  deep  study  and  intense  thought,  even  in 
the  company  of  those  who  are  talking,  laughing,  singing,  or 
in  the  midst  of  any  noise.  This  is  a valuable  acquisition  and 
one  that  should  be  sought  after  by  every  one,  since  all  of  us 
are  liable  to  be  thrown  into  such  circumstances,  that  we 
must  work,  think,  and  transact  business  in  noise  and  confu- 
sion. 

649.  Tliebesl  Time  for  Study. — 8.  We  see  from  this  sub- 
ject that  the  best  time  for  study  is  in  the  morning,  for  then  the 
brain  is  rested,  and  can  with  the  greatest  vigor  and  alacrity 
engage  in  its  efforts.  But  here  the  fact  presents  itself,  that 
the  morning  is  the  best  time  for  physical  exercise,  and  to 


017.  How  should  tho  brain  and  nervous  system  be  worked  ? 64S.  What  is  said  of  the 
value  of  mental  abstraction  ? 049.  What  is  tho  best  time  for  study  ? 


AND  PHYSIOLOGY. 


355 


•which  shall  we  give  the  preference  ? Shall  we  deprive  our 
bodies  of  exercise,  or  shall  we  give  up  the  best  efforts  of  the 
brain?  Without  hesitancy,  as  a general  ru'e^  we  should 
say,  attend  to  the  physical  exercise  first,  for  if  the  general 
health  be  broken  down,  the  brain  will  sympathize,  and  then 
close  mental  effort  will  be  at  an  end.  Hence,  although  morn- 
ing is  the  best  time  for  study,  yet  we  must  not  take  the  whole 
of  it  for  that  purpose,  but  must  share  it  with  exercise.  To  a 
student  who  is  passing  through  a long  course  of  study,  early 
rising  and  retiring,  and  generally  exercise  in  the  morning 
before  commencing  study,  will  tend  to  preserve  and  invigorate 
health.  Studying  late  at  night  and  sleeping  long  in  the 
morning,  are  injurious  to  no  class  of  people  more  than  to  the 
hard  student. 

650.  Pernicious  Effect  of  Tobacco  on  the  Brain —9. 
The  effect  of  tobacco  on  the  brain  is  thus  described,  in  his 
medical  lectures,  by  Dr.  Solly,  an  eminent  physiologist  and 
practical  physician:  ‘‘I  Avould  caution  you,  as  students, 
from  excesses  in  the  use  of  tobacco  and  smoking,  and  I would 
advise  you  to  disabuse  your  patients’  minds  of  the  idea  that 
it  is  harmless.  I have  had  a large  experience  of  brain  dis- 
ease, and  am  satisfied  now  that  smoking  is  a most  noxious 
habit.  I know  of  no  cause  or  agent  that  tends  so  much  to 
bring  on  functional  disease,  and  through  this  in  the  end  to 
lead  to  organic  diseases  of  the  brain,  as  excessive  use  of  to- 
bacco.” 

651.  Power  of  the  Feelings  over  the  Nervous  System. — 
10.  It  is  wonderful  and  interesting  to  see  what  is  the  power 
exerted  by  the  feelings  and  emotions  upon  the  nervous  sys- 
tem, and  through  that  upon  the  whole  body.  Let  the  farmer 
feel  that  his  severe  labor  is  sure  to  bring  him  in  good  crops, 
and  how  happily  does  he  persevere  in  his  severe  toil  month 
after  month.  And  if  the  merchant  can  only  know  that  his 


But  how  shall  exercise  and  study  both  be  properly  attended  to  ? What  is  wSaid  of  early 
rising?  650.  How  does  tobacco  affect  the  brain ? 651.  What  effect  have  the  emotions 
upon  the  physical  system  ? 


3oG  HITCHCOCK’S  ANATOMY 

gains  arc  great,  how  incessantly  will  he  work  day  and  night, 
and  yet  consider  his  no  hard  life.  But  if  there  be  no  encour- 
agement, no  prospect  of  reward  to  the  working-man  in  his 
employment,  what  drudgery  does  it  become  ! Nay,  how  posi- 
tively injurious  to  health  and  vigor  of  body  and  mind. 

G52.  To  the  scholar,  however,  this  principle  is  much  more 
important  than  to  him  who  labors  only  with  the  muscles,  since 
these  organs  can  be  worked  to  a considerable  extent  with  an 
unwilling  mind ; but  to  Avork  a brain  already  depressed  and 
discouraged  is  much  more  difficult,  and  sure  to  bring  on  grave 
disease.  When  the  spirits  are  light  and  the,  mind  free,  the 
memory  can  be  more  readily  stored  with  facts  and  principles, 
and  the  reasoning  powers  more  easily  developed.  It  is  hence 
the  duty  of  teachers  to  make  study  as  pleasant  and  attractive 
as  possible  ; it  becomes  those  Avho  select  the  location  and  con- 
struct the  buildings  of  colleges,  academies,  and  school-houses, 
to  have  a reference  to  taste  and  comfort  in  their  plans,  so  that 
physical  inconvenience  may  not  render  study  irksome,  and 
that  the  taste  of  the  student  may  be  improved  as  much  as  pos- 
sible by  the  construction  and  arrangements  of  these  buildings. 

653.  Control  of  the  Nervous  System  by  Moral  and 
Religious  Feelings. — 11.  Finally,  of  all  the  sources  and 
promoters  of  health,  correct  moral  and  religious  feelings  and 
principles  are  among  the  most  powerful.  The  reaction  of  a 
guilty  conscience  upon  the  body,  in  obstructing  the  functions 
and  in  bringing  on  weakness  and  premature  decay,  is  well 
known.  Equally  powerful  in  promoting  health  and  longevity 
is  an  approving  conscience.  A cheerful  acquiescence  in  the 
divine  will  has  often  done  more  to  restore  the  invalid  and 
maintain  good  health  against  disease,  than  all  medical  reme- 
dies ; while  pure  and  ennobling  sentiments  and  religious  hopes 
have  sometimes  been  more  efficacious  to  prolong  life  on  earth 
t’lan  Jill  otlier  liygicnic  prescriptions. 


052.  Wliiit  cfViict  lias  plonsiiraMo  foolinfjs  on  tho  progress  of  the  scholar?  053.  State 
the  valiin  of  an  upproviuj^  coiibciciice  upon  all  claases  of  society,  as  it  simply  respects 
phybical  hcalLli. 


AND  PHYSIOLOGY. 


357 


COMPARATIVE  NEUROLOGY. 


654.  Amono;  all  the  higher 
mammals  we  are  able  to  trace 
nearly  all  the  different  parts 
of  the  nervous  system  as  they 
are  exhibited  and  arranged  in 
man,  though  many  of  them 
are  considerably  modified. 

655.  Weight  of  Brains. — 
The  relative  weight  of  the 
brain  is  greater  in  the  smaller 
animals.  Thus,  in  the  mouse 
it  is  said  to  be  the  weight 
of  the  body.  In  the  elephant 
the  weight  of  the  brain  is 


Fig.  329. 


Brain  of  Squirrel  laid  open.  B,  Cere- 
brum. D,  Cerebellum.  C,  Optic  Lobes. 
that,,  Thalamus  Opticus,  c,  s,  Corpus 
Striatum. 


Fig.  330. 


Upper  and  Under  Surface  of  Brain  of  Rabbit.  A,  B,  D,  as  before.  oZ,  Olfactive  Lobes, 
op,  Optic  Nerve,  mo.  Motor  Oculi.  cm,  Corpora  Mamillafia.  c,  c.  Crus  Cerebri,  pv^ 
PonsVarolii,  per,  Patheticus.  tri,  Trifacial,  ab,  Abducens.  fac^  Facial.  Audi- 
tory. Vagus,  s.  Spinal  Accessory.  App.,  Hypoglossal. 


655.  What  is  said  of  the  size  of  brains  ? 


858 


HITCHCOCK’S  ANATOMY 


the  weight  of  the  body;  in  the  ox,  yljjth;  in  the  fox, 
v j-th;  while  in  man  it  is  the  weight  of  the  body. 

656.  Proportion  of  the  AViilth  of  Brain  and  Spinal 
Cord  in  Man  and  other  Mammalia. — This,  as  well  as  the 
comparison  of  cerebral  mass  and  cerebral  nerves,  between  man 
and  other  animals,  is  interesting.  The  breadth  of  the  spinal 
marrow  is,  to  that  of  the  breadth  of  the  brain,  in  man,  as 
1:7;  in  the  dog,  as  1 : 2. 

657.  Cerebral  Nerves. — “The  cerebral  nerves  correspond 
to  those  of  man.  The  first  pair,  however,  forms  in  some  de- 
gree an  exception,  for  though  not  absent  in  all  the  whale 
family,  it  is  wanting  in  the  dolphins.  In  most  mammals  the 
olfactory  nerves  are  thick  and  have  a cavity  in  them.  The 
fifth  pair  of  nerves  is,  in  many  mammals,  of  peculiar  strength 
and  thickness  when  compared  with  that  pair  in  man.^’ 

658.  Sympathetic  System.  — “The  nervous  system  of 
organic  life— the  great  sympathetic — is  formed,  as  far  as  in- 
vestigations indicate,  essentially  as  in  man.’'  It  is  situated 
mostly  in  the  cavities  of  the  thorax  and  abdomen,  and  follows 
the  course  of  the  blood  vessels. 

659.  Tentorium. — The  tentorium  cerebelli,  which  in  man 
is  a simple  tough  membrane  that  separates  the  cerebrum  from 
the  cerebellum,  is  very  delicate  in  some  animals,  as  the  horse 
and  dolphin ; while  in  the  cat  it  is  supported  by  a bony  plate 
springing  from  the  skull,  and  is  a very  firm  membrane.  Its 
use  to  protect  the  brain  in  those  animals  whose  movements 
are  at  times  violent  and  sudden,  and  especially  those  that  leap 
great  distances. 

660.  Spinal  Nerves. — The  Spinal  nerves  also,  in  general 
appearance,  are  like  those  in  man.  The  number  of  pairs 
varies  in  diffiTcnt  species,  as  might  be  inferred  from  the  dif- 
fering number  of  their  vertebrae. 

C50.  State  tlio  i)roportion  of  llio  width  of  the  brain  and  spinal  cord.  C57.  What  is  said 
of  the  c<5rcbral  nerves  of  animals?  058.  Wliat  is  said  of  the  sympathetic  system?  659. 
What  is  said  of  the  tentorium  ? 060.  What  of  the  spinal  nerves  of  animals  f 


AND  PHYSIOLOGY. 


359 


661.  Actual  Proportion  between  Cerebrum  and  Cere- 
bellum.— According  to  Cuvier,  the  proportion  of  the  cere- 
bellum to  the  cerebrum,  by  weight,  in  the  baboon,  is  as 
1:7;  in  the  dog,  1:8;  in  the  sheep,  1:5;  and  in  the  horse, 
1:7. 

662.  Spinal  Cord. — The  essential  difference  between  the 
spinal  cord  in  man  and  the  lower  mammalia,  is  its  greater 
length,  and  a narrow  canal  which  runs  longitudinally  through 
the  middle  of  it. 

663.  Nervous  System  of  Birds.— The  brain  of  birds  is 

characterized  by  the  smallness  of  the  hemispheres,  though 
more  fully  developed  than  in 
reptiles  and  fishes.  In  the 

sparrow  the  weight  of  the 
brain  to  the  whole  body  is  as 
1:25;  in  the  goose,  1 : 300  ; 
and  in  the  cassowary,  1:1000. 

It  is  destitute  of  convolutions, 
or  in  other  words  is  perfectly 
smooth  on  its  surface,  and  has 
large  cavities  or  ventricles  con- 
tained  in  it : and,  as  in  mam- 
mals,  the  mass  of  the  brain  Optic  GangUa.  D,  Cerebellum,  fir,  Pineal 
is  greater  than  that  of  the 

spinal  cord.  The  pairs  of  the  cerebral  nerves  are  the  same 
as  in  mammals ; also  the  principal  divisions  are  the  same. 
The  cerebellum,  as  in  man,  exhibits  the  arbor  vitae  when  cut 
through  vertically. 

664.  Nervous  System  of  Reptiles. — The  brain  of  rep- 


Fm.  331. 


661.  What  is  the  proportion  between  the  weight  of  the  cerebrum  and  cerebellum  in 
some  of  the  lower  animals  ? 662.  What  is  the  essential  difference  betwee"'  the  spinal  cord 
of  man  and  that  of  most  quadrupeds  ? 663.  How  is  the  brain  of  birds  characterized  ? 
Give  some  of  the  proportional  weights  of  it  compared  with  that  of  the  whole  body  V 

IG 


360 


HITCHCOCK’S  ANATOMY 


tiles  constitutes  but  a very 
small  part  of  the  body.  In 
the  frog  the  proportion  to  the 
Avhole  weight  of  the  body  is 
as  1:172;  in  the  Coluber 
matrix  (snake),  1 : 792  ; in  a 
turtle,  1 : 5688.  The  hemi- 
spheres are  smooth  and  hollow 
internally.  The  optic  lobes 
are  large  in  proportion  to  the 
size  of  the  eyes,  and  are  hoi-, 
low  internally.  The  cerebel- 
lum of  frogs  is  merely  a thin 
plate  of  nervous  matter. 

665.  Nervous  System  of 
Fishes. — We  find  the  lowest 

Brain  of  Turtle.  A,  Olfactive  Ganglia.  , , 

B,  Cerebrum.  C,  Optic  Ganglia.  D,  Cere-  development  Ot  the  nerVOUS 

system  among  vertebrates  in 
the  fishes.  The  brain  here  does  not  fill  the  whole  cranial 
cavity,  so  that  between  the  brain  and  dura  mater  there  is 
found  a quantity  of  loose  cellular  tissue,  with  which  is  inter- 
spersed a fluid  oil.  The  brain  in  weight  does  not  equal  that 
of  the  spinal  cord,  nor  is  it  but  a little  broader  than  the  cord. 
Its  weight  in  proportion  to  that  of  the  body  is  about  75^0  oth 
part.  It  is  composed  of  eight  lobes,  partly  in  pairs,  and 
partly  unpaired  behind  one  another,  which  seem  to  correspond 
to  the  cerebellum  (divided),  corpora  quadrigemina,  thalami 
optici,  and  medulla  oblongata. 

666.  Elcclrical  Organs  in  Fishes. — There  are  at  least 
seven  species  of  fish  that  possess  the  power  of  giving  electric 
discharges.  The  organs  which  accomplish  this  in  the  Torpedo 
are  two  large  crescent-like  bodies  (see  Fig.  334),  which  are 


00-1,  Wluit  snifl  of  tlio  brnin  of  roi)tilfis?  State  its  comparative  size  with  that  of  the 
wliole  Ixxly.  005.  State  some  of  the  peculiarities  of  the  brain  in  fishes.  What  is  its 
relative*,  wciirht?  000.  What  is  said  of  the  electrical  orgaus  of  some  fishes?  Give  tho 
anatomy  of  these  organs. 


AND  PHYSIOLOGY. 
Pia.  333. 


301 


Brains  of  Fishes.  A,  Olfactive  Lobes  or  Ganglia.  B,  Cerebral  Hemispheres.  C Op- 
tic  Lobes.  D,  Cerebellum,  ol.  Olfactory  Nerve,  op,  Optic  Nerve,  pa,  Patheticifs 
«<,,  Motor  Ocu  i.  aj  Abducens.  Trifacial.  /«,  F.aclal.  AadL’y.  A: 
gus.  tt,  Tubercles  or  Ganglia  of  the  Trifacial.  U,  Tubercles  of  the  Va<^us. 


made  up  of  a large  number  of  short,  six-sided  prisms,  and 
are  abundantly  supplied  with  nerves.  And  as  these  organs 
are  made  up  of  prisms,  which  stand  end  upon  end,  and  not 
side  by  side  only,  as  they  appear  in  the  cut,  the  idea  seems 


362 


HITCHCOCK’S  ANATOMY 


Tig.  334.  Fig.  335. 


Electrical  Apparatus  of  Torpedo.  5,  Nervous  System  of  an  Articulate. 

BranchifE.  c,  Brain,  e,  Electric  Organ. 

(7,  Cartilage  of  Cranium,  me,  Spinal  Cord,  w,  Nerves  to  the  Pectoral  Fins,  nl^  Lat- 
eral Nerves  to  the  Body,  np^  Large  Nerves  (Pncumogastric)  to  the  Electric  Organ, 
o,  Eye. 

plausible  that  they  may  he  regarded  as  Voltaic  piles,  or  a 
reservoir  of  electric  power  which  the  fish  can  discharge  at 
will.  And  it  is  necessary  for  the  generation  of  this  electrical 
discharge  that  the  integrity  of  the  nervous  system  be  main- 
tained. 

G67.  Nervous  System  in  Articulata. — In  the  Crusta- 
ceans the  nervous  system  consists  of  ganglia  and  cords.  The 
central  ganglion  may  be  regarded  as  a brain,  which  sends  off 
nerves  of  vision,  audition,  feeling,  and  smelling.  A splanch- 
nic or  sympathetic  nerve  is  also  found,  as  in  the  Arachnoidea 
and  Annelida.  The  two  latter  classes  have  ganglia,  which 


CC7.  State  tlio  general  plan  of  the  nervous  system  in  articulates. 


AND  PHYSIOLOGY. 


363 


Fig.  336. 

may  be  called  a brain.  In 
Insects  the  central  parts 
of  the  nervous  system  con- 
sist of  a brain  and  a ven- 
tral cord/^  as  is  shown  on 
Fig.  336.  In  some  of  the 
lower  tribes  of  Articulates, 
as  the  Helminthes  and  Rota- 
toria, the  nervous  system 
is  feebly  and  indistinctly  de- 
veloped. 

668.  Reflex  Actions  in  Ar*  Nervous  System  of  a Beetle. 

t i c u 1 a t e s . — This  sub-king- 
dom is  remarkable  for  its  reflex  actions.  Thus  if  the  head  of  a 
centipede  be  cut  off  while  it  is  in  motion,  the  body  will  con- 
tinue to  move  by  the  action  of  its  legs ; and  the  same  will 
take  place,  if  the  body  is  divided  into  several  segments.  The 
explanation  is  as  follows.  ^^The  body  is  moved  forward  by 
the  regular  and  successive  action  of  its  legs,  as  in  the  natural 
state  : but  its  movements  are  always  forwards,  never  back- 
wards, and  are  only  directed  to  one  side,  when  the  forward 
movement  is  checked  by  an  interposed  obstacle.  Hence,  al- 
though they  might  seem  to  indicate  consciousness  and  a guid- 
ing will,  they  do  not  so  in  reality : for  they  are  carried  on  as 
it  were  mechanically,  and  show  no  direction  or  object,  no 
avoidance  of  danger.  If  the  body  be  opposed  in  its  progress 
by  an  object  of  not  more  than  half  its  height,  it  mounts  over 
it,  and  moves  directly  onwards,  as  in  its  natural  state  : but  if 
the  obstacle  be  equal  to  its  own  height,  its  progress  is  ar- 
rested, and  the  cut  extremity  of  the  body  remains  forced  up 
against  the  opposing  substance,  the  legs  still  continuing  to 
moveP 


What  is  the  name  of  the  principal  ganglia?  668.  What  is  said  of  the  reflex  actions 
of  articulate  animals  ? What  are  these  reflex  actions  sometimes  mistaken  for  ? Give 
the  example. 


364 


HITCHCOCK’S  ANATOMY 


669.  Nervous  System  of  Molluscs— Cephalic  Gang- 
lia.— Pedal  Ganglia.  — Parieto- Splanchnic  Ganglia. 
— In  most  of  the  Molluscs  the  nervous  system  is  well  de- 

Fig.  337. 


Nervous  System  of  Argonauta  Argo.  A,  As  seen  in  front.  B,  As  viewed  in  profile, 
fihowing  tho  relations  of  the  Nervous  Centers  to  the  Buccal  Mass,  a,  The  Esophagus  b, 
and  tho  Eye  c.  a,  Cephalic  Ganglion,  Buccal  Ganglion,  c,  Sub-Esophageal  Gang- 
lion. </,  (/,  Stellate  Ganglia  of  tho  Mantle.  6,  Visceral  Ganglion.  / Nerves  of  tho 
Anns,  with  Ganglionic  Enlargements.  (/,  Optic  Nerves,  h,  A,  Eyes,  i,  Branchial 
Nerves  with  their  Ganglia. 


AND  PHYSIOLOGY. 


365 


veloped;  the  most  so  in  the  Cephalopods,  which  are  the 
highest  in  organization.  In  these  we  find  a central  organ 
quite  like  a brain,  enveloped  by  a membrane  analogous  to 
the  Dura  Mater.  This  system  is  shown  on  Fig.  837.  The 
general  arrangement  is  that  of  three  principal  pairs  of  ganglia 
with  nerves  proceeding  from  them.  The  first  pair  is  called 
the  Cephalic  ganglia,  which  is  the  largest,  and  is  located 
above  or  on  the  sides  of  the  esophagus,  with  a collar  of  nerves 
surrounding  that  tube.  This  gives  off  nerves  to  the  organs 
of  vision  and  taste,  and  to  the  muscular  apparatus  of  the  mouth. 
The  second  pair,  called  the  Pedal  ganglia,  is  located  beneath 
the  esophagus,  giving  off  nerves  to  the  foot  and  the  organs  of 
hearing,  when  this  sense  is  not  actually  located  in  the  foot. 
The  third  pair,  the  Parieto-Splanchnic  ganglia,  are  usually 
found  in  the  posterior  part  of  the  body  giving  nerves  to  the 
muscular  and  sensitive  walls  of  the  body,  the  respiratory  ap- 
paratus, the  heart  and  large  blood  vessels. 


670.  Nervous  System  of  Radiates. — Need  of  a Nerv- 
ous System. — Among  the  higher  Radiates  a nervous  system 
of  inferior  organization  can  be  found.  For  the  most  part  it 
consists  of  a ring  of  nervous  238. 


matter  about  the  mouth, 
which  sends  off  branches  in 
different  directions.  In 
Medusae  the  nervous  system 
consists  of  a simple  cord,  of 
a string  of  ovate  cells,  form- 
ing a rino^  aroun^^  the  lower 
margin  of  the  animal.” — 
Agassiz.  (Fig.  338.)  Gang- 
lia, 


Nervous  System  of  Star-Fish,  g,  g.  Live 
Ganglia. 


or  reservoirs  of  force  can  but  seldom  be  found. 


671.  Among  the  Infusoria  no  nervous  system  can  be  de- 
tected, and  if  any  exist,  its  participation  in  the  general  course 


C60.  What  is  the  principal  arrangement  of  tlie  nervous  system  among  molluscs?  670. 
What  is  the  nervous  system  of  the  radiates?  C7l.  How  is  the  nervous  system  among 
Kadiates  ? 


3G6 


HITCHCOCK’S  ANATOMY 


of  vital  action  must  be  very  trifling.  For  the  simplest  ofiice 
of  a nervous  system  is  to  establish  a communication  between 
the  different  parts  of  the  body ; but  if  every  part  of  the  body 
has  similar  endowments,  there  can  be  no  object  in  such  com- 
munication. For  instance,  where  every  part  of  the  surface — 
as  is  the  case  in  those  animals — is  equally  susceptible  of  ab- 
sorption, there  can  be  no  need  of  a circulating  system,  and 
where  contractility  seems  to  be  diffused  through  the  body 
alike,  a nervous  system  would  be  superfluous. 


671.  What  of  the  ncrrous  sygiem  of  Infusorbw 


CHAPTER  EIGHTH. 


THE  INLETS  TO  THE  SOUL.— THE  SENSES. 


GENERAL  REMARKS. 

672.  The  Senses.— Dependent  on  the  Mind.— These  are 
commonly  known  under  the  name  of  senses.  Five  are  usually 
reckoned.  Seeing,  Hearing,  Tasting,  Feeling,  and  Smelling; 
and  it  is  by  these  alone  that  we  are  made  acquainted  with  ex- 
ternal objects.  In  other  words,  sensation  may  be  defined  as 
the  consciousness  of  impressions.  The  mind,  for  aught  we 
know,  might  be  able  to  carry  on  its  functions  of  thinking, 
reasoning,  and  memory,  and  also  be  conscious  of  its  own  ex- 
istence, if  it  were  deprived  of  the  senses : but  it  could  not 
make  itself  felt  on  other  minds,  nor  increase  in  knowledge  and 
discipline  without  their  aid.  And  although  the  primary  ob- 
ject of  the  senses  is  to  promote  physical  enjoyment,  yet  their 
highest  and  noblest  use  is  to  subserve  the  purposes  of  the 
mind. 

673.  Senses  best  Developed  in  lower  Animals. — In 
man  the  senses  are  not  so  fully  developed  as  in  most  of  the 
lower  animals.  But  this  deficiency  is  much  more  than  com- 
pensated by  the  superiority  of  his  intellect. 

674.  Effect  of  excessive  Use  of  the  S e n s c s .—Excessive 
indulgence  of  any  of  the  senses  is  apt  to  produce  painful  in- 
stead of  pleasurable  sensations.  Thus  heat  of  a moderate 

G72,  What  are  the  inlets  of  the  soul  ? Is  mind  necessary  for  the  existence  of  sense? 
What  is  the  primary  use  of  the  senses?  What  should  be  their  hiarhest  us3?  673.  In 
what  animals  are  the  senses  the  most  perfectly  developed?  674.  How  does  excessive 
indulgence  affect  the  senses? 


16* 


363  HITCHCOCK’S  ANATOMY 

temperature  is  always  agreeable,  but  painful  if  much  in- 
creased. Many  odors  snuffed  in  small  quantity  are  pleasant, 
but  when  given  to  satiety,  become  disgusting.  The  probable 
design  of  this  provision  seems  to  be  to  prevent  injury  by  an 
inordinate  stimulation  of  any  of  the  nerves.  For  instances  are 
on  record,  where  the  mucous  membrane  of  the  nostrils  has 
been  severely  affected  by  the  fumes  of  ammonia  given  in 
fainting. 

675.  Habit  makes  painful  Sensations  pleasant —It 
is  a curious  but  interesting  fact  that  the  pain  excited  by  un- 
accustomed sensations  may  sometimes  be  exchanged  for  its 
opposite,  after  the  system  has  become  habituated  to  them. 
Thus  tobacco  and  alcoholic  liquors  are  at  first  disagreeable  to 
most  persons ; but  when  the  disgust  has  been  overcome  by 
any  means  a love  for  them  succeeds,  and  generally  a strong 
craving  for  excessive  indulgence  also. 

676.  Nerves  of  Special  Sense  can  perform  but  one 
Function. — The  nerves  of  special  sense  are  incapable  of  per- 
forming any  function  except  that  for  which  they  were  orig- 
inally designed.  Thus  the  optic  nerve  can  perform  the  func- 
tion of  vision  only,  the  olfactory  only  that  of  smelling,  and 
the  auditory  only  that  of  hearing. 

677.  Effect  of  Belief  on  our  Sensations. — The  effect 
of  previous  belief  in  modifying  our  sensations,  is  shown  in 
the  two  cases  copied  from  Carpenter’s  Physiology.  “A 
clergyman  told  me  that  some  time  ago  suspicions  were  enter- 
tained in  liis  parish,  of  a woman  who  was  supposed  to  have 
poisoned  her  newly  born  infant.  The  coflSn  was  exhumed, 
and  the  procurator  fiscal,  who  attended  with  the  medical  men 
to  examine  the  body,  declared  that  he  already  perceived  the 
odor  of  decomposition,  which  made  him  feel  faint,  and  in  con- 
sequence he  withdrew.  But  on  opening  the  coffin,  it  was 


What  Instance  of  this  from  odors?  075,  How  docs  habit  sometimes  affect  painful  sen- 
ftallons?  Whut  examples?  <J76.  Wiiat  is  said  of  the  function  of  the  nerves  of  special 
Bonse  ? 677.  Ilow  docs  our  belief  affect  our  sensations?  Give  the  instance  of  the  infant. 


AND  PHYSIOLOGY. 


369 


found  to  be  empty ; and  it  was  afterwards  ascertained  that  no 
child  had  been  born,  and  consequently  no  murder  committed. 
The  second  case  is  yet  more  remarkable.  A butcher  was 
brought  into  the  shop  of  Mr.  McFarlan,  the  dimggist,  from 
the  market  place  opposite,  laboring  under  a terrible  accident. 
The  man  on  trying  to  hook  up  a heavy  piece  of  meat  above 
his  head,  slipped,  and  the  sharp  hook  penetrated  his  arm,  so 
that  he  himself  was  suspended.  On  being  examined,  he  was 
pale,  almost  pulseless,  and  expressed  himself  as  suffering  the 
acutest  agony.  The  arm  could  not  be  moved  without  causing 
excessive  pain;. and  in  cutting  off  the  sleere,  he  frequently 
cried  out : yet  when  the  arm  was  exposed,  it  was  found  to  be 
quite  uninjured,  the  hook  having  only  traversed  the  sleeve  of 
his  coat ! !” 


THE  SENSE  OF  VISION. 

DEFINITIONS  AND  DESCRIPTIONS, 

678.  The  chief  organ  of  this  sense  is  the  eye,  although  its 
appendages  perform  very  important  secondary  functions. 

679.  Anatomy  of  the  Eye. — The  human  eye  is  nearly 
globular  in  form,  with  a diameter  a little  less  than  one  inch, 
the  lateral  diameter  being  one  twentieth  of  an  inch  less  than 
the  antero-posterior.  (Fig.  339,  p.  370.)  In  general  struc- 
ture it  is  made  up  of  three  membranes,  and  three  humors, 
or  transparent  media,  and  is  covered  on  the  surface  exposed 
to  the  air  by  mucous  membrane,  which  also  lines  the  inside 
of  the  lid,  so  that  the  two  surfaces  at  some  points  are  always 
in  contact. 

680.  Sclerotica. — The  membrane  which  covers  the  larcrer 
portion  of  the  eye  is  called  the  Sclerotica,  from  the  Greek 

Give  the  instance  of  the  butcher.  673.  What  is  the  chief  organ  of  sight?  679.  What 
is  the  shape  of  the  eye?  Its  diameter?  Of  how  many  media  and  membranes  is  it 
made  up  ? 


370 


HITCH  cock’s  anatomy 


FlO.  339. 


Longitudinal  Section  of  the  Globe  of  the  Eye.  1,  Sclerotic,  thicker  behind  than  In 
front.  2,  Cornea,  received  within  Anterior  Margin  of  Sclerotic,  and  connected  with  it  by 
means  of  a beveled  edge.  8,  Choroid,  connected  anteriorly  with  (4,)  Ciliary  ligament, 
and  (5,)  Ciliary  Processes.  6,  Iris.  7,  Pupil.  8,  Third  Layer  of  Eye,  Retina  terminating 
anteriorly  by  abrupt  border  at  commencement  of  Ciliary  Processes.  9,  Canal  of  Petit, 
encircles  the  Lens  (12) ; the  thin  layer  in  front  of  this  canal  is  the  Zonula  Ciliaris,  a pro- 
longation of  Vascular  Layer  of  Retina  to  the  Lens.  10,  Anterior  Chamber  of  Eye  con- 
taining Aqueous  Humor;  the  lining  membrane,  by  which  the  humor  is  secreted,  is 
represented  in  diagram.  11,  Posterior  Chamber.  12,  Lens,  more  convex  behind  than 
before,  enclosed  in  its  proper  Capsule.  13,  Vitreous  Humor  enclosed  in  Hyaloid  Mem- 
brane, and  in  cells  formed  in  its  interior  by  that  membrane.  14,  Tubular  Sheath  of 
Hyaloid  Membrane,  which  serves  for  the  passage  of  the  Artery  of  Capsule  of  the  Lens. 
15,  Neurilemma  of  Optic  Nerve.  16,  Arteria  Centralis  Retinae,  embedded  in  the  center. 


signifying  hard,  because  it  is  a firm  and  stout  membrane.  Its 
color  is  nearly  white,  covering  the  posterior  four  fifths  of  the 
eye,  it  is  commonly  called  the  white  of  the  eye,  and  is  thickest 
in  its  posterior  parts. 

681.  Cornea. — The  external  covering  of  the  front  fifth 
part  of  the  eye  is  called  the  Cornea,  from  the  Latin  word 
meaning  horn-like,  and  in  two  respects  it  bears  the  same  rela- 
tion to  the  ball  of  the  eye,  as  the  crystal  does  to  the  watch, 
since  it  is  fitted  into  the  sclerotic  by  a beveled  edge,  as  is  a 
watch-glass,  and  also  because  it  is  perfectly  transparent.  The 
blood-vessels  of  this  membrane  are  among  the  smallest  in  the 
body,  being  too  small  to  allow  the  passage  of  the  blood-cor- 
puscles, and  only  convey  the  plasma  or  serum. 


CBO.  I>escribo  the  sclerotic  coat.  G8i.  What  is  the  cornea?  To  what  may  it  be  com- 
pared in  the  watch  ? 


AND  PHYSIOLOGY 


371 


682.  Choroid  Coat —Iris. 

— Ciliary  Processes.— The 
middle  coat  of  the  eye  is 
made  up  of  three  portions, 
the  Choroid  membrane,  the 
Iris,  and  the  Ciliary  pro- 
cesses. The  first,  Choroid,  is 
named  from  the  fact  that  it  is 
entirely  made  up  of  blood- 
vessels, of  a chocolate-brown 
color  on  the  outside,  and  a 
deep  black  on  the  inside.  It 
covers  the  posterior  four  fifths 
of  the  eye,  and  corresponds 
to  the  sclerotic  coat  outside 
of  it.  The  Iris,  so  called  from 
the  diversity  of  color  which 

Plan  of  the  Structures  in  the  Fore  Part  of  the  Eye,  seen  in  Section.  1,  Conjunctiva. 
2,  Sclerotica.  3,  Cornea.  4,  Choroid.  5,  Annulus  Albidus ; before  this  is  is  seen  the 
Canal  of  Fontana.  6,  Ciliary  Processes.  7,  Iris.  8,  Retina.  9,  Hyaloid  Membrane.  10, 
Canal  of  Petit  (made  too  large).  11,  Membrane  of  the  Aqueous  Humor  (too  thick.)  c/. 
Aqueous  Humor;  Anterior  Chamber,  and  (a,)  Posterior  Chamber.  &,  Crystalline  Lens, 
c,  Vitreous  Humor. 

Fia.  341. 


6 


Choroid  Coat  of  the  Eye.  1,  Curved  lines  marking  the  arrangement  of  Venae  Vorti- 
cosae.  2,  2,  Ciliary  Nerves.  3,  A long  Ciliary  Artery  and  Nerve.  4,  Ciliary  Ligament. 
5,  Iris.  6,  Pupil. 


632.  Of  what  three  portions  is  the  choroid  coat  composed  ? Give  their  names.  De- 
scribe the  Iris. 


872 


HITCHCOCK’S  ANATOMY 


it  presents  in  diflferent  persons — and  it  is  the  color  of  this 
which  we  mean  when  we  speak  of  the  color  of  the  eye — cor- 
responds in  position  to  the  cornea  lying  immediately  under  it. 

FiG.  342. 


Fig.  343. 


External  View  of  the  Iris.  Anterior  Segment  of  a Transverse  Section 

of  the  Globe  of  the  Eye  seen  from  within. 
1,  Divided  edge  of  the  three  Tunics  ; Sclerotic,  Choroid  (the  dark  layer),  and 
Ketina.  2,  Pupil.  3,  Iris,  the  surface  presented  to  view  in  this  section  being 
the  Uvea.  4,  Ciliary  Processes.  5,  Scalloped  Anterior  Border  of  the  Ketina, 

It  is  circular  in  form,  containing  a few  muscular  fibers,  with 
a circular  opening  through  its  center,  from  one  third  to  one 
twentieth  of  an  inch  in  diameter,  which  is  known  as  the  pupil. 
The  Ciliary  processes  are  minute  triangular  folds  of  the  Cho- 
roid coat,  which  lie  upon  the  interior  surface  of  the  iris,  with 
their  bases  directed  toward  the  pupil.  They  are  about  sixty 
in  number,  and  are  divided  into  large  and  small,  the  latter 
being  placed  between  the  former.  The  Pigmentum  Nigrum, 
or  black  paint,  is  an  extremely  tenuous  membrane,  which 
lines  the  inside  of  the  choroid  coat.  It  is  of  a jet  black  color, 
and  is  easily  destroyed  merely  by  allowing  a stream  of  water 
to  fall  upon  it. 

683.  Retina. — The  inner  membrane  of  the  eye  is  the  Re- 
tina, which  is  merely  an  expansion  of  the  optic  nerve,  upon 


Wluit  Is  the  diiiinctcr  of  tlio  iris?  What  arc  tlie  ciliary  processes?  How  many  are 
tlioro?  What  is  the  pigmentum  nigrum  ? 683.  Describe  the  retina.  , 


AND  PIIYvSIOLOOY 


373 


the  inner  side  of  a hollow  sphere,  formed  hy  the  membranes 
already  mentioned. 

684.  Microscopic  Structure  of  these  Membranes. — 
The  structure  of  these  membranes,  as  revealed  by  the  micro- 
scope, is  very  complex.  The  Cornea  is  made  up  of  four  sim- 
ple membranes,  the  Choroid  of  three,  and  the  Retina  of  four. 


Tig.  344. 


Vertical  Section  of  tlie  Human  Retina  and  Hyaloid  Membrane,  h,  Hyaloid  Membrane. 
4',  Nuclei  on  its  inner  surface,  c,  Layer  of  Transparent  Cells,  connecting  the  Hyaloid 
and  Retina,  c',  Separate  Cell  enlarged  by  imbibition  of  water,  Gray  Nervous  Layer, 
with  its  Capillaries.  1,  Its  Fibrous  Lamina.  2,  Its  Vesicular  Lamina.  1',  Shred  of  Fi- 
brous lamina  detached.  2',  Vesicle  and  Nucleus  detached,  g.  Granular  Layer.  3,  Light 
Lamina  frequently  seen.  g\  Detached  Nucleated  Particle  of  the  Granular  Layer,  w,  Ja- 
cob’s Membrane,  m'.  Appearance  of  its  Particles,  when  detached,  m".  Its  Outer  Sur- 
face.— Magnified  320  diameters. 


The  Sclerotic  is  for  the  most  part  made  up  of  white  fibrous 
tissue,  and  a large  portion  of  the  Choroid  coat  is  composed  of 
blood-vessels,  although  the  inner  membrane — the  Pigmentum 
Nigrum  or  black  paint — consists  of  minute  six-sided  cells  re- 
sembling a tesselated  pavement.  The  Retina  is  for  the  most 
part  made  up  of  the  different  forms  of  nervous  tissue  and  its 
membranes. 


634.  Give  the  microscopic  structure  of  the  cornea.  Of  the  choroid,  the  pigment,  and 
the  retina. 


74 


HITCHCOCK’S  ANATOI^rY 


685.  Humors  of  the  Eye;  Aqueous— Of  the  three  Hu- 
mors or  liquid  substances  composing  the  eye,  the  Aqueous  or 
Avatery  is  situated  in  the  anterior  portion  of  this  organ  behind 
the  cornea,  and  in  front  of  the  crystalline  humor  soon  to  Ix) 
described.  It  is  a liquid  like  water,  with  an  alkaline  taste, 
and  only  a few  drops  in  quantity.  The  Iris  is  placed  directly 
in  the  middle  of  this  fluid. 

686.  The  Lens. — The  Crystalline  Lens  or  Humor  (so 
called  because  it  refracts  light  and  is  transparent  like  a crys- 
tal) is  a double  convex  lens,  the  posterior  convexity  being 


Fig.  345.  Fig.  346. 


Front  View  of  the  Crystalline  Lens.  Side  View  of  the  Lens.  1,  Anterior  Face. 

2,  Posterior  Face.  3,  Circumference. 


greater  than  the  anterior,  and  is  located  directly  behind  the 
pupil,  so  that  all  the  light  Avhich  enters  the  eye,  must  pass 
through  this  and  be  refracted.  This  lens  is  made  up  of  con- 
centric layers  like  an  onion,  and  also  of  three  triangular  seg- 
ments, with  their  sharp  edges  directed  towards  the  center, 
both  of  which  structures,  by  boiling  the  lens  in  water  for  a 
short  time,  can  be  readily  seen.  Fig.  347  represents  the 

difierence  in  diameters 
of  the  lens  at  difierent 
periods  of  life,  a,  rep- 
resents it  at  birth,  6,  at 
six  years  of  age,  c,  its 
appearance  in  an  adult, 
and  rf,  after  it  has  been 


Fig.  347. 


0 


Crystalline  Lens,  a,  At  birth.  6,  At  six  years 
old.  c,  Adult,  rf,  Altered  by  alcohol. 


C85.  How  many  humors  are  there  in  the  eye?  Describe  the  aqueous.  ^6.  What  is 
the  crystalline  humor  ? What  kind  of  a Ions  is  it?  Of  how  many  segments  is  it  made  up  f 


AND  PHYSIOLOGY. 


375 


hardened  and  partially  divided  into  segments  by  an  immersion 
in  alcohol. 

687.  Vitreous. — The  Vitreous  Humor  (from  its  resem- 
blance to  glass)  is  of  the  form  of  a sphere,  with  the  anterior 
portion  removed,  and  constitutes  seven  eighths  of  the  globe  of 
the  eye.  It  is  a transparent  fluid  enclosed  in  a transparent 
membrane,  and  through  its  central  portion  from  the  entrance 
of  the  optic  nerve,  there  passes  a small  artery  to  the  lens, 
which  supplies  it  with  blood. 

688.  Lachrymal  Gland. — Nasal  Duel. — At  the  outer  angle 
of  each  eye  is  found  a gland  called  the  Lachrymal  gland,  nearly 
three  fourths  of  an  inch  in  length,  and  of  a flattened  oval 


Fig.  348. 


Posterior  View  of  the  Eyelids  and  Lachrymal  Gland.  1,  1,  Orbicularis  Palbebrarum 
Muscle.  2,  Borders  of  the  Lids.  3,  Lachrymal  Gland.  4,  Its  Ducts  opening  in  the  Up- 
per Lid.  6,  Conjunctiva  covering  the  Lids.  6,  Puncta  Lachrymalia.  7,  Lachrymal  Ca- 
runcle as  seen  from  behind. 

shape.  (Fig.  348.)  Passing  from  this  gland  to  the  eye,  are  from 
eight  to  twelve  small  ducts,  which  open  upon  the  under  side 
of  the  lid  near  its  edge,  about  one  twentieth  of  an  inch  apart, 
which  carry  the  tears  to  the  eye.  By  continual  winking  this 


687.  From  what  docs  the  vitreous  humor  get  its  name?  Describe  it.  688.  Where  aro 
the  lachrymal  glands  situated?  What  is  their  size ? How  many  ducts  have  they  ? What 
do  they  secrete  ? Of  what  use  Is  winking? 


37G 


HITCHCOCK’S  anatomy 


Fig.  349. 


Lachrymal  Canals.  1,  Puncta  Lachry- 
malia.  2,  Cul-de-Sac  at  the  Orbital  End 
of  the  Canal.  3,  Course  of  each  Canal  to 
the  Saccus  Lacryrnalis.  4,  5,  Saccus  La- 
crymalis.  G,  Lower  Part  of  the  Ductus 
ad  Nasum. 


fluid  is  uniformly  distributcMl 
over  the  Avhole  hall  of  the 
eye,  and  the  excess  is  carried 
away  from  the  eye  liy  the 
two  lachrymal  canals,  which 
commence  at  the  two  little 
projections  near  the  inner 
angle  of  each  lid  of  the  eye, 
appearing  like  minute  black 
specks.  Both  of  these  very  soon 
unite  into  a larger  tube  called 
the  nasal  duct,  (Fig.  349.) 
which  descends  inwardly  and 
empties  itself  upon  the  nostrils. 

G89.  Eyebrows . — The 
Eyebrows  are  projecting 
arches  of  fat  and  skin,  cov- 
ered with  short  and  thick 


Fig.  350. 


hairs  which  encircle  the 
upper  portion  of  the 
eye.  They  are  provided 
with  muscles,  so  that 
they  can  be  made  to 
shade  the  eye  more  or 
less  perfectly,  as  ne- 
cessity may  require. 

690.  Eyelids.— The 
Eyelids  are  movable 
membranous  and  mus- 
cular coverings  which 
are  placed  directly  up- 
on the  eyeball,  and  are 
designed  for  protective  organs  against  mechanical  violence  and 
too  powerful  light.  Their  free  edges  are  called  T|irsal  Carti- 


Front  View  of  the  Left  Eye — moderately  opened. 
1,  Supercilia.  2,  Cilia  of  each  Eyelid.  3,  Inferior 
Palpebra.  4,  Internal  Canthus.  5,  External  Can- 
thus.  6,  Caruncula  lacryrnalis.  7,  Plica  Semilu- 
naris. 8,  Eyeball.  9,  Pupil. 


Where  are  t.lio  lachrymal  canals  and  what  do  they  carry?  What  is  the  nasal  duct? 
CS9.  Describe  the  eyebrows.  090.  What  are  the  eyelids?  What  arc  their  edges  made  up 
of?  What  glands  directly  in  them  ? 


AND  PHYSIOLOGY, 


377 


lages,  directly  in  the  substance  of  which  is  placed  a large 
quantity  of  minute  glands,  called  Meibomian  Glands. 


Fig.  351. 


Fig.  352. 


Meibomian  Glands  seen  from  the  Inner  or  Ocu- 
lar Surface  of  the  Eyelids,  with  the  Lachrymal 
Gland— of  the  Eight  Side,  a,  Palpebral  Conjunc- 
tiva. 1,  Lachrymal  Gland.  2,  Openings  of  Lachry- 
mal Ducts.  3,  Lachrymal  Puncta.  6,  Meibomian 
Glands. 

691.  Muscles  of  the  Eye. — The 
Ball  of  the  eye  is  moved  by  six  distinct 
muscles,  four  straight  and  two  oblique 
muscles,  as  is  shown  in  the  cut.  Their 
names  are  Rectus  Superior  and  Inferior, 
nal,  and  Superior  and  Inferior  Oblique. 


Meibomian  Gland  highly 
magnified. 

External  and  Inter- 


Muscles  of  the  Eyeball.  1,  A small  FiG.  353. 

Fragment  of  the  Sphenoid  Bone 
around  entrance  of  Optic  Nerve  into 
Orbit.  2,  Optic  Nerve.  3,  Globe  of 
Eye.  4,  Levator  Palpebrje  Muscle. 

5,  Superior  Oblique  Muscle.  6,  Its 
Cartilaginous  Pulley.  7,  Its  reflected 
Tendon.  8,  Inferior  Oblique  Muscle; 
the  small  square  knob  at  its  com- 
mencement is  a piece  of  its  bony 
origin  broken  off.  9,  Superior  Rec- 
tus. 10,  Internal  Rectus  almost  con- 
cealed by  Optic  Nerve.  11,  Part  of  External  Rectus,  showing  its  two  heads  of  origin. 
12,  Extremity  of  External  Rectus,  at  its  Insertion;  the  intermediate  portion  of  muscle 


having  been  removed.  13,  Inferior  Rectus.  14,  Tunica  Albuginea  formed  by  expansion 
of  tendons  of  four  recti. 


691.  How  many  muscles  for  moving  the  eyeball  ? Give  their  names. 


378 


HITCHCOCK’S  ANATOMY 


FUNCTIONS  OF  THE  EYE. 

692.  The  primary  and  obvious  use  of  the  eye  is  to  receive 
the  form  and  color  of  different  objects,  and  to  transmit  them 
to  the  brain. 

693.  Use  of  llie  Coats — Sclerotica — Cornea — Choroid  — 
Black  Paint — Iris — Ciliary  Processes — The  Retina. — The 
use  of  the  firm  and  hard  sclerotic  coat  is  to  give  a firm  attach- 
ment to  the  muscles  which  move  the  eye,  and  also  secure  pro- 
tection to  the  delicate  parts  within.  The  cornea  is  tough  but 
transparent,  so  that  the  anterior  portion  of  the  eye  may  be 
firm  and  at  the  same  time  admit  the  rays  of  light.  The  cho- 
roid coat  furnishes  the  blood  to  the  eye,  it  being  for  the  most 
part  entirely  made  up  of  blood-vessels.  It  also  secretes  the 
black  paint  (Fig.  288),  which  is  of  great  service  in  absorb- 
ing the  superfluous  or  wandering  rays  of  light  which  otherwise 
would  obscure  the  image  on  the  retina.  A similar  provision 
is  made  by  painting  black  the  tube  of  the  telescope  and  mi- 
croscope. The  iris  regulates  the  amount  of  light  entering  the 
ball,  by  its  contraction  and  expansion.  This  function  is  per- 
formed by  the  radiated  and  circular  muscular  fibers,  the 
latter  of  which  contract  by  the  stimulus  of  strong  light; 
but  if  the  light  be  feeble,  the  radiated  contract,  and  thus 
enlarge  the  pupil.  The  retina,  with  the  vitreous  humor 
in  front  and  the  black  paint  directly  behind  it,  receives 
the  image  of  the  object  before  the  eye.  It  bears  the  same 
relation  to  the  other  parts  of  the  eye  as  the  silvered  or  glass 
plate  does  in  the  camera  of  the  photographist.  This  impres- 
sion is  carried  to  the  brain  by  means  of  the  optic  nerve. 

694.  Use  of  the  Humors — Aqueous— The  Lens— Vitreous^ 
— Of  the  three  humors  or  media  o^  the  eye,  the  aqueous  is 
the  least  important,  since  if  by  accident  or  operation  it  is  re- 

092.  state  the  use  of  the  eye.  C93.  Give  the  use  of  the  sclerotic  coat.  Of  the  cornea. 
What  does  the  cliorold  furnish  to  the  eye?  Of  wliat  service  is  the  black  paint?  What 
docs  the  Iris  do?  What  is  the  function  of  tlie  ciliary  processes?  What  is  the  use  of  the 
retina?  C94.  Which  Is  the  least  Important  of  the  humors  ? 


AND  PPIYSIOLOGY. 


moved,  nature  will  soon  replace  it ; but  this  is  true  of  no 
other  medium.  The  aqueous  humor,  however,  is  of  great  use 
to  keep  the  front  parts  of  the  eye  in  a soft  and  elastic  condi- 
tion, and  also  to  furnish  a medium  in  which  the  iris  may 
readily  be  contracted  and  relaxed.  It  also  aids  in  properly 
refracting  the  rays  of  light,  so  that  the  most  perfect  image 
may  be  formed  on  the  retina.  The  use  of  the  crystalline  lens 
is  also  to  refract  the  rays  of  light,  so  that  an  image  of  suffi- 
ciently small  size  may  be  formed  on  the  retina.  Otherwise, 
when  we  look  at  any  object  larger  than  the  diameter  of  the 
pupil,  we  should  be  unable  to  see  it,  only  by  successively 
looking  at  minute  portions  of  it.  The  vitreous  humor  assists 
in  the  same  refraction  of  the  rays,  and  incidentally  subserves 
the  purpose  of  fixing  at  a proper  distance  the  lens,  so  that  the 
image  may  be  formed  exactly  at  that  point  on  the  retina  called 
the  focus,  where  it  will  be  the  most  distinct. 

695.  Need  of  Three  Media.— But  what  is  the  necessity  for 
three  media  of  refraction,  and  why  will  not  the  crystalline  lens 
answer  the  whole  purpose  ? This  is  owing  to  some  of  the 
properties  of  light.  Light  is  composed  of  seven  rays  or  colors, 
some  of  which  are  more  easily  refracted  than  others  ; that  is, 
some  rays  are  bent  farther  from  a perpendicular  to  the  sur- 
face than  others.  Hence,  upon  the  edges  of  an  image  formed 
by  a single  lens,  every  part  of  which  is  of  the  same  density, 
we  should  see  several  of  the  prismatic  colors,  which  would  give 
an  indistinct  image.  In  the  telescope  and  microscope  this 
difficulty  is  remedied  by  forming  a lens  of  crown  and  flint 
glass,  one  of  which  has  a stronger  dispersive  or  refractive 
power  than  the  other.  In  the  eye  the  same  error  is  obviated 
by  means  of  the  crystalline  lens,  which  has  a greater  refrac- 
tive power  than  the  vitreous  humor,  and  consequently,  when 
the  ray  is  too  much  refracted  by  the  crystalline  lens,  a corn- 


state  the  use  of  the  aqueous.  The  use  of  the  lens.  What  does  the  vitreous  humor  aid 
in?  695.  What  is  the  need  of  three  humors  ? IIow  many  distinct  colors  does  light  con- 
sist of  ? What  similar  purpose  do  lenses  of  different  densities  answer  in  telescopes? 
Which  of  the  three  humors  has  the  greatest  refractive  power  ? 


880 


HITCHCOCK’S  ANATOMY 


pcnsation  is  effected  by  the  vitreous  humor,  which  refracts  less 
than  the  lens. 

696.  The  Secretion  of  the  Lachrymal  Clands.— The  lach- 
rymal gland  is  designed  to  secrete  a saltish  fluid  known  as  tho 
Tears.  This  is  of  great  service  in  lubricating  and  keeping 
moist  the  surface  of  the  eyeball,  so  that  it  may  move  readily 
in  its  socket,  and  also  to  keep  the  cornea  from  becoming  hard 
and  dim.  The  tears  also  moisten  the  back  part  of  the  nostrils, 
and  are  ultimately  poured  into  the  pharynx.  The  amount  of 
tears  which  is  daily  secreted  is  estimated  at  four  ounces, 
and  it  is  greatly  increased  by  strong  emotions,  whether  pleas- 
ant or  sorrowful,  as  it  is  well  known  that  a person  is  apt  to 
cry  when  very  sad  or  very  happy. 

697.  Service  of  the  Eyelids — Necessity  of  Constantly 
Winking — Eyelashes. — The  eyelids  are  of  service  to  keep 
the  light  from  the  eyes  when  it  is  too  intense,  or  when  it  is 
necessary  to  exclude  it  entirely,  as  during  sleep.  Another 
valuable  service  which  they  perform  is  to  spread  the  tears 
constantly  and  uniformly  over  the  eyeball.  This  is  the  rea- 
son why  we  are  constantly  but  unconsciously  winking  during 
every  few  seconds  of  our  waking  hours.  The  eyelashes  which 
line  the  edges  of  the  lids,  prevent  the  perspiration  which  is 
secreted  on  the  lids  from  entering  the  eye,  and  thus  irritating 
it,  since  by  the  law  of  capillary  attraction  the  tears  will  run 
towards  the  free  extremity  of  the  hair,  where  they  will  accu- 
mulate to  such  a size  that  they  drop  off.  The  eyelashes  also 
prevent,  in  some  degree,  dust  from  entering  the  eye. 

698.  Use  of  the  Eyebrows. — The  eyebrows  perform  a 
similar  office  to  the  eyelids,  though  not  so  important.  The 
hairs  which  cover  them,  like  the  lashes,  convey  away  the  per- 
spiration from  the  forehead,  and  allow  it  to  fall  in  front  of  the 
eye,  and  not  directly  upon  the  ball ; while,  by  means  of  the 


G9G.  Wliiit  is  tlio  secretion  of  tho  lachrymal  gland?  What  is  the  use  of  the  tears? 
What  quantity  of  tears  are  secreted  daily?  G97.  Of  what  service  are  the  eyelids?  Why 
clo  wo  constantly  wink?  Of  what  service  are  tho  eyelashes?  698.  What  service  do  the 
eyebrows  perform? 


AND  PHYSIOLOGY. 


881 


muscles  attached  to  the  integuments,  whenever  it  is  desired 
they  bring  the  brows  in  front  of  and  above  the  eye  in  such  a 
manner  as  to  afford  it  a very  considerable  protection  from  ex- 
cessive light. 

699.  Short  and  long-Siglitedncss.— The  phenomena  of 
short  and  long-sightedness  are  worthy  of  a passing  notice. 
Short-sightedness  results  where  the  lens  of  the  eye  has  too 
much  convexity,  which  causes  the  image  to  be  formed  in  front 
of  the  retina.  In  such  persons  the  eye  generally  has  greater 
prominence  than  in  others.  But  persons  thus  affected  will 
probably  in  later  years  have  better  eye-sight  than  if  short- 
sightedness had  not  existed.  A too  much  flattened  state  of 
the  lens  occurs  in  those  who  are  long-sighted.  This  is  gener- 
ally the  case  with  those  somewhat  advanced  in  life.  In  this 
case  the  distinct  image  will  be  formed  behind  the  retina,  and 
it  requires  a convex  lens,  in  the  form  of  spectacles,  to  correct 
the  error. 

700.  Other  Interesting  Phenomena  of  Vision.— A few 
other  phenomena  connected  with  the  function  of  vision  de- 
serve attention.  One  is  the  fact,  that  although  we  have  two 
eyes  and  two  distinct  images  are  transmitted  to  the  brain, 
yet  but  one  object  is  seen.  And  if  we  look  at  an  object  with 
only  one  eye,  we  see  the  image  nearly  as  distinct  as  with  both 
eyes.  Another  is,  that  although  the  image  on  the  retina  is 
inverted,  yet  to  the  mind  it  appears  in  its  true  position.  For, 
since  the  rays  of  light  pass  through  the  lens  in  nearly  straight 
lines,  the  ray  coming,  for  instance,  from  the  top  of  a tree,  will 
fall  upon  the  lowest  part  of  the  retina,  while  the  ray  coming 
from  the  bottom  will  strike  the  upper  part,  and  hence  the 
image  will  be  inverted,  although  to  the  mind^s  eye’’  it  will 
be  erect.  Another  fact  is  equally  wonderful.  We  are  able 
to  see  with  distinctness  an  object  only  a few  inches  from  our 


699.  Whivt  is  the  cause  of  short-sightedness?  What  is  the  reason  of  long-sightedness  ? 
What  kind  a lens  is  required  for  long-sighted  people,  and  why  ? 700.  What  curious 
facts  coniiectetl  with  the  physiology  of  vision  ? 


382 


HITCHCOCK’S  ANATOMY 


eyes,  and  almost  instantly,  by  turning  them  to  a mountain 
top  several  miles  distant,  we  can  see  an  object  there  with  per- 
fect cleaarness.  No  optical  instrument  can  be  made  which 
will  so  quickly  do  this,  for  it  is  necessary  to  make  a new  ad- 
justment of  the  lenses  to  adapt  it  to  different  distances,  but 
the  eye  is  at  once  ready.  It  is  supposed  that  this  adjustment 
is  effected  by  a shortening  or  lengthening  of  the  diameter  of 
the  crystalline  lens,  or  by  drawing  the  lens  towards  the  pos- 
terior part  of  the  eye,  by  means  of  a few  muscular  fibers 
called  the  ciliary  muscle,  running  from  the  bones  of  the  nose 
to  the  cornea,  which  by  their  contraction  would  force  the 
aqueous  humor  upon  the  crystalline  lens  in  such  a manner  as 
to  flatten  it,  and  by  a relaxation  of  the  same  fibers  a dilata- 
tion in  an  antero-posterior  direction  is  effected,  and  that  in- 
stantly. 

701.  Experiment  for  Seeing  the  Arteries  of  tne^s  own 
Eye. — The  image  of  the  arteries  of  one’s  own  eye  can  be 
readily  seen  in  the  following  manner.  In  a dark  room  place 
the  left  hand  over  the  left  eye,  and  in  the  right  hand  hold  a 
lighted  candle  by  the  right  side  of  the  head,  and  very  near 
to  it.  Then  with  the  right  eye  open,  looking  towards  the 
darkened  wall,  move  the  candle  up  and  down  rather  quickly, 
and  in  a few  seconds  dark  branches  will  appear  at  a short  dis- 
tance from  the  eye,  looking  like  the  limbs  of  a tree,  which  are 
images  of  the  arteries  distributed  on  the  retina. 

702.  limits  of  Vision. — What  is  the  size  of  minute  ob- 
jects that  can  be  seen  by  the  naked  eye  ? Ehrenberg,  fn 
eminent  microscopist,  says  that  nearly  all  eyes  have  eqrjal 
power  to  discern  minute  objects,  whether  long  or  short-sighced. 
The  smallest  square  magnitude  visible  to  the  naked  (jye, 
cither  of  white  particles  on  a dark  ground, or  the  reverse,  is 
about  the  ^ J^^th  of  an  inch.  Brilliant  particles  which  pow- 


llfiw  is  Iho  tolcscopic  and  the  microscopic  power  of  the  eye  explained?  Ilowcan 
we  see  the  iinaf?o  of  llio  arteries  of  our  own  eyes?  702.  What  is  the  sinallesc  square  sur- 
face that  can  bo  seen  with  the  naked  eye  ? 


AND  PHTSIOLOGT. 


883 


erfully  reflect  light  may  be  distinctly  seen  when  not  half  the 
size  of  the  foregoing.  Thus  gold  dust  the  ttV part  of  an 
inch  in  diameter  is  visible  in  common  daylight.  Lines  may 
be  more  readily  seen  than  points.  Opaque  threads  4 Vo  o th  of 
an  inch  in  diameter  can  be  seen  when  held  towards  the  light. 
Attention  also  greatly  helps  to  discern  minute  objects,  or  at 
least  to  retain  them  in  sight  when  once  pointed  out.  Thus 
we  are  often  able  to  see  a faint  star  in  the  sky  or  a ship  in  the 
horizon  after  they  have  been  pointed  out  to  us,  although  they 
were  not  seen  before.  “ I myself,’^  says  Ehrenberg,  can 
not  see  stV^  th  of  an  inch,  black  or  white,  at  twelve  inches 
distance  ; but  having  found  it  at  from  four  to  five  inches 
distance,  I can  remove  it  to  twelve  inches  and  still  see  the 
object  plainly.’’ 

703.  Color  Blindness.— Many  people  are  afflicted  with  an 
inability  to  distinguish  certain  colors  of  the  solar  spectrum. 
This  is  cadled  Color  Blindness,  or  Daltonism. 

704.  Formerly  it  was  supposed  that  this  afiection  was  very 
rare,  bu^c  later  researches  show  it  to  be  quite  common.  Ac- 
cording to  experiments  made  by  Dr.  Wilson  upon  1154  per- 
sons in*  Edinburgh  in  1852  and  1853,  it  was  found  that — 

1 in  55  confonnds  red  with  brown. 

1 in  60  confounds  brown  with  green. 

1 in  43  confounds  blue  with  green. 

ujlence  one  in  every  17.9  persons  is  color  blind. 

/THE  SENSE  OF  VISION  IN  ANIMALS. 

705.  Tapctiim— Pupil— Nictitating  Membrane— llarde- 
riaii  Gland. — The  general  anatomy  of  the  eye  of  mammals 
difie  rs  but  slightly  from  that  of  man.  Between  the  sclerotic 
and  c’.horoid  in  some  animals  is  found  another  membrane  of  a 

How  is  .’t  with  brilliant  particles?  How  is  the  ready  vision  of  lines  compared  with 
points?  How  small  a thread  can  be  seen  by  the  naked  eye?  What  elfeet  has  the  fa- 
miliarity wiU’i  an  object  ? 703.  What  is  color  blindness  ? How  often  is  this  peculiarity 
found?  What  colors  are  most  commonly  confounded ? 

17 


384 


HITCHCOCK’S  ANATOMY 


metallic  brilliancy,  with  different  shade  of  color,  known  as 
the  Tapetum.  In  horses  and  cows  it  has  a variegated  luster 
of  green  and  blue,  while  in  the  tiger,  cat,  and  whale  it  is  of 
a silvery  brightness.  The  shape  of  the  pupil  in  the  wolf 
and  dog,  which  need  vision  in  all  directions,  is  circular ; while 
the  fox  and  cat,  which  need  a vertical  range  more  than  any 
other,  have  a perpendicular  slit  only.  In  cattle  and  the  more 
timid  grazing  animals  which  obtain  their  food  from  the  ground, 
and  need  to  look  behind  with  ease  when  pursued,  the  pupil  is 
a horizontal  ellipse.  Nearly  all  mammals  except  man  and 
the  apes,  have  a third  lid,  which  is  a transpareit  membrane 
that  is  frequently  slid  over  the  ball  by  a pecukar  muscular 
apparatus.  This  is  called  the  haw’’  or  Nictitating  Mem- 
brane, and,  especially  in  birds,  serves  the  purpose  of  remov- 
ing impurities  from  the  eye,  and  also  of  spreading  the  secre- 
tions over  it,  in  order  to  keep  it  moist  and  transparent.  In 
addition  to  the  lachrymal  gland,  in  all  animals  which  have 
the  third  lid  there  is  another  gland  called  the  Harderian  Gland, 
which  prepares  another  secretion  similar  to  and  for  nearly  the 
same  purpose  as  the  lachrymal. 

706.  Eyes  of  Birds  — Pecten  Marsupium. — All  birds, 
without  exception,  are  provided  with  perfect  and  well  deveb 
oped  eyes.  They  are  always  large,  and  largest  in  birds  of 
prey.  They  are  but  slightly  movable  themselves,  but  this 
want  of  motion  is  compensated  by  the  great  mobility  ol.  the 
head.  The  sclerotic  coat  is  strengthened  in  front  by  a series 
of  bony  plates,  fourteen  or  fifteen  in  number,  interposed  be- 
tween its  fibrous  layers,  a great  use  of  w^hich  is  to  give  at- 
tachment to  the  special  muscular  apparatus  for  adapting  the 
eye  to  see  objects  at  different  distances.  The  anterior  chan^iber 
is  proportionally  larger  than  in  any  other  animals,  so  that  the 
iris  is  far  back  from  the  cornea.  The  iris  has  different  shades 
of  color,  commonly  yellow  or  brownish.  The  yellow  color  of 

705.  What  is  tin;  tapotuiii  ? WHiat  is  its  color?  W^liat  is  the  shape  of  the  pupil  in  the 
■wolf,  do}',  and  ill  (Jiittle ? What  is  the  Nictitatin<j  membrane?  Of  what  fijervice  is  the 
“huw?”  For  what  jmrpose  is  the  llardorian  "land  ? TOG.  What  is  said  o<l  the  perfection 
of  eyes  in  birds?  How  is  the  sclerotic  coat  strengthened  in  them  ? 


AND  PHYSIOLOGY. 


385 


this  part  in  the  owl  is  owing  to  the  presence  of  cells  contain- 
ing fat.  A curious  structure  is  found  in  the  eye  of  birds  that 
is  found  in  no  other  animal.  It  is  called  the  Pecten  Mar- 
supium,”  and  consists  of  a layer  of  blood-vessels  arranged  in 
several  plications  varying  greatly  in  size.  It  extends  some- 
times as  far  forwards  as  the  lens,  and  is  covered  by  black  pig- 
ment. Its  probable  use  is  that  of  absorbing  rays  that  enter 
the  eye  obliquely,  and  thus  rendering  sight  from  a forward 
direction  more  definite  and  sharp.  The  membrana  nictitans 
and  the  Harderian  glands  are  present  in  these  animals  in  their 
fullest  perfection. 

707.  Eyes  of  Reptiles, — All  reptiles  have  two  eyes.  In 
most,  especially  in  serpents,  they  are  small  in  comparison 
with  the  size  of  the  body  ; in  the  frog,  however,  in  the  gechos 
and  chameleons  they  are  large.  In  some  they  are  covered  by 
the  skin.  In  the  serpents  there  are  no  eyelids,  but  the  skin 
which  covers  them  is  kept  moist  by  a lachrymal  gland,  and 
thus  performs  the  service  of  a lid.  In  other  reptiles  there 
are  three  lids,  the  middle  one  of  which  moves  at  right  angles 
to  the  other  two.  The  lachrymal  gland  often  is  very  large. 
In  some  turtles  and  lizards  there  is  a ring  of  bony  plates 
which  supports  the  eyeball.  The  lens  has  different  degrees 
of  sphericity  in  different  animals. 

708.  Eye  of  Fishes— Pigmentary  Spots.— The  eyes  of 
fisi  les  are  remarkable  for  the  great  size  and  spherical  form  of 
th^  lens,  which  is  necessary  in  order  to  give  sufScient  refrac- 
tio  n to  the  rays  of  light  that  come  from  the  dense  medium  in 
wliich  they  live.  The  size  of  the  lens  varies  greatly,  being 
largest  in  the  bony  fishes  and  smallest  in  those  which  lie 
bui'ied  in  the  mud  like  the  eel.  The  lowest  stage,  however, 
is  s<3en  in  the  amphioxus,  a condition  which  greatly  resembles 


What  makes  the  yellow  color  of  the  iris  in  birds?  What  is  the  pecten  marsupiura? 
What  is  Ils  use?  707.  What  is  said  of  the  eyes  of  reptiles?  What  of  the  bony  plates 
in  the  eyer)all?  708.  What  characterizes  the  eyes  of  fishes?  What  ones  have  the 
largest? 


386 


IT  I T C TI  C O C K ’ S A N A T O ]Sr  Y 


that  of  the  lowest  invertebrata,  being  nothing  but  two  pig- 
mentary spots.  The  eye  is  but  slightly  movable  in  fishes, 
since  the  body,  and  consequently  the  head,  can  be  so  readily 
moved  in  any  direction  through  the  water. 


Tig.  354.  709.  C 0 in  p 0 11  n (I  Eyes 

, — Number  of  F accls. — 
The  eyes  of  many  of  the 
articulate  animals  are  con* 
structed  upon  the  com- 
pound type,  that  is,  the 
visual  organs  are  made  up 
of  an  aggregatic  n of  jingle 
eyes  placed  upon  each  side 
of  the  head,  each  one  of 
which  is  a complete  visual 

Head  and  Compound  Eyes  of  the  Bee^  show-  instrument,  but  Can  rC- 
inj?  the  Ocelli  in  sitn  on  one  side  (A),  and  dis- 
placed on  the  other  (B).  a,  a,  Stemmata. 

5,  Antenn®. 

which  come  to  it  from  a particular  direction.  In  many  in- 
sects each  composite  eye  forms  a hemispherical  protuber- 
ance upon  the  side  of  the  head,  which,  when  examined  bj  the 

Fig.  355.  \ 

A 


ceive  and  bring  to  a focus 
only  those  rays  cf  light 


/ 

A,  Section  of  the  Eye  of  Melolontha  Vulgaris  (Cockchaffer).  B,  A portion  more ’highly 
Magnified,  r/,  Facets  of  the  Cornea.  ?>,  Transparent  Pyramids  surrounded  wi*ch  Pig* 
iiuiiit.  c,  Fibers  of  ihe  (>[)tic  Nerve.  (1^  Trunk  of  the  Optic  Nerve. 

-?  ; 

W'hat  are  the  pigmentary  spots?  709.  What  are  compound  eyes?  Whats'.ab-kiiigdoia 

do  they  characterize?  How  does  the  eye  ttpi»ear  on  many  insects? 


AND  PHYSIOLOGY. 


87 


Fig.  356. 


magnifying  glass,  is  found  to  be  made  up  of  a vast  number 
of  facets,  which  are  generally  hexagonal.  In  the  common 
house  fly  there  are  4,000  in  each  eye,  in  the  dragon  fly 
24,000,  and  in  one  species  of  the  beetle  25,000.  Each  one 
of  these  facets  is  found  to  be  the  end  of  a little  eye,  the  frus- 
trum  of  a slender  pyramid  standing  by  its  apex  on  a bulbous 
expansion  of  the  optic  nerve.  The  interior  of  this  pyramid 
is  filled  with  a trans- 
parent substance  which 
represents  the  vitreous 
humor,  while  between 
the  frustra  is  found  the 
black  pigment.  Both 

surfaces  of  these  facets  FossU  TriboUte  constructed  on  the  same 

are  found  to  be  convex,  plan- 

and  it  has  been  calculated  that  the  focus  of  these  lenses  would 
be  at  a point  just  at  the  extremity  of  the  pyramid  where  it 
joins  the  optic  nerve.  And  since  the  rays  of  light  entering 
onp  of  these  facets  can  not  enter  the  other  on  account  of  the 
black  pigment  intervening  between  them,  the  range  of  vision 
to  the  insect  would  necessarily  be  very  limited  were  it  not  for 
their  enormous  multiplication,  by  which  in  reality  a separate 
eye  is  provided  for  every  point  to  be  viewed,  thus  giving  to 
fhe  insect  as  perfect  an  apparatus  of  vision  as  we  have,  al- 
‘fiough  immovably  fixed  on  the  body. 

710.  S t e m m a t a . — Besides  the  composite  eyes,  insects  usu- 
ally have  a small  number  of  simple  eyes  situated  upon  the  top 
* f the  head,  called  Stemmata.  If  they  are  covered  with  paint, 
t he  movements  of  the  insect  are  constantly  upward. 


711.  Other  Articulates. — A few  insects  that  live  in  dark 
places  have  no  eyes.  Some  Crustaceans  have  compound  eyes 
withiut  facets,  and  others  with  them.  Some  Annelids  have 
eyes,  others  none.  The  Rotatoria  have  vision,  but  the  Ilel- 


What  nuLiber  of  facets  are  there  in  the  house  fly  and  in  the  dragon  fly?  Give  the  an- 
atomy of  each  facet  or  pyramid.  710.  What  other  organs  of  vision  besides  compound 
eyes  do  insects  have  ? If  the  stemmata  are  removed  what  is  the  result  ? Til.  What 
of  the  eyes  of  art>,ulates  ? 


388 


ir  I T C II  C O € K ’ S ANATOMY 


minths  are  without  eyes.  Among  Araclinida  (spiders)  the 
eyes  bear  a near  relation  to  the  vertebrate  type  of  eyes.  Their 
number  is  much  less  than  among  the  other  articulata,  seldom 
more  than  eight,  and  are  to  be  compared  more  with  stemmata 
than  with  compound  eyes.  Sometimes  these  are  collected 
into  one  mass  upon  the  second  segment  of  the  body,  and  some- 
times they  are  arranged  symmetrically  upon  the  median  line. 

712.  Eyes  of  Molluscs, — The  organs  of  vision  in  the 
Acephala  are  numerous,  rising  as  high  as  forty  in  the  genus 
Pinna,  where  they  are  placed  in  the  mantle.  The  Cephalo- 
phora  have  generally  two  eyes.  In  the  Cephalopoda  the  eyes 
are  disproportionately  large,  and  possess  nearly  all  the  parts 
found  in  the  eyes  of  vertebrates. 

\ 713.  Eyes  of  Radiates. — The  Polypi  show  a sensibility 

to  light,  but  no  eyes  have  been  discovered  in  them.  The 
Acalephse  seem  to  have  the  sense  of  vision,  and  Agassiz  seems 
to  have  ascertained  the  presence  of  an  organ  for  this  purpose 
in  some  of  them.  It  is  more  doubtful  in  respect  to  the  Echi- 
noderms. 

WTiat  eyes  have  spiders?  712.  What  are  the  eyes  of  molluscs?  713.  What  is  said 
the  organs  of  vision  among  radiates  ? 

i 

i 

,1 


AND  PHYSIOLOGY 


389 


THE  SENSE  OF  HEARING. 

DEFINITIONS  AND  DESCRIPTIONS. 

714.  Parts  of  the  Ear, — The  organ  of  hearing  is  made 
up  of  three  distinct  portions : the  Pinna  or  external  ear,  the 
Tympanum  or  middle  ear,  and  the  Labyrinth  or  internal  ear. 

715.  The  Pinna, — The  Pinna,  commonly  known  as  the 
Ear,  is  a cartilaginous  plate  with  numerous  irregularities  upon 
its  surface,  and  having  upon  it  a few  muscular  fibers,  which 

357.  Fig.  358. 


A View  of  the  Left  Ear  in  its  Natural 
state.  1,  2,  The  origin  and  termination 
of  the  Helix.  3,  The  Anti-Helix.  4,  The 
Anti-Tragus.  5,  The  Tragus.  6,  The  Lo- 
bus  of  the  External  Ear.  7,  Points  to  the 
Scapha,  and  is  on  the  front  and  top  of  the 
Pinna.  8,  The  Concha.  9,  The  Meatus 
Auditorius  Externus. 


An  Anterior  View  of  the  External  Ear, 
as  well  as  of  the  Meatus  Auditorius,  Laby- 
rinth, etc.  1,  The  Opening  into  the  Ear 
at  the  bottom  of  the  Concha,  2,  The  Mea- 
tus Auditorius  Externus  or  Cartilagin- 
ous Canal,  3,  The  Mcrnbrana  Tympani 
stretched  upon  its  King,  4,  The  Malleus. 
5,  The  Stapes,  6,  The  Labyrinth. 


714.  What  are  the  three  parts  of  the  organ  of  hearing?  715.  Describe  the  pinna. 


390  IIITCnCOCK’S  ANATOMY 

are  in  fact  rudimentary  muscles,  5 in  number.  In  some  men 
they  have  been  so  fully  developed  that  the  cars  could  bo 
moved  by  their  action,  while  among  quadrupeds  there  arc  but 
few  that  do  not  possess  this  power.  The  Pinna  somewhat 
resembles  a funnel,  forming  at  its  base  an  irregular  tube  called 
the  Auditory  Canal,  about  half  an  inch  in  diameter  and  an 
inch  in  length,  which  terminates  with  the  Tympanum.  A 
few  stiff  hairs  arc  found  upon  the  sides  of  this  canal,  and  in 
the  lining  membrane  some  glands,  which  secrete  the  wax  of 
the  car. 

716.  The  Tympanum —Membrana  Tympani,— little 
Bones  of  the  Ear. — The  Tympanum  is  an  irregular  cav- 
ity located  in  the  petrous  portion  of  the  Temporal  bone, 
measuring  rather  more  than  one  half  inch  in  its  longest 
diameter.  At  the  point  where  the  Auditory  Canal  joins 

the  Tympanum,  the 
Membrana  Tympani  is 
found,  wdiich  is  simply 
an  impervious  mem- 
brane stretched  between 
the  tw^o  cavities,  dip- 
ping inwards  at  an  an- 
gle of  forty-five  degrees. 
To  this  membrane  are 
attached  three  muscles 
for  the  purpose  of  ren- 
dering this  membrane 
lax  or  tense,  as  may  be 

View  of  tho  Cavity  of  the  Tympanum,  the  Ossicula  Auditus,  and  their  Muscles,  magni- 
fied. «,  rt,  Cavity  of  tho  Tympanum.  Membrana  Tympani,  or  rather  the  osseous 
circle  to  which  it  is  attached,  c,  Handle  of  the  Malleus,  resting  on  the  middle  of  the 
Membrana  Tymi)ani.  </,  Head  of  tho  Malleus  articulating  with  the  Incus,  e.  Long 
Handle  of  tho  Malleus,  passing  into  the  Glenoidal  Fissure;  the  Anterior  Muscle  of  tho 
Malleus  is  attached  to  it.  / Internal  Muscle  of  the  Malleus,  Anvil.  7i,  Lenticular 
Lone,  if  Stapes.  7%  Muscular  Stapedius. 


Fig.  359. 

g d 


a boh 


Can  the  ear  ever  bo  moved  ? How  many  rudimentary  muscles  are  placed  on  it?  716. 
W hat  is  tho  tympanum  ? Describe  tho  membrana  tympani. 


AND  PHYSIOLOGY.  391 

Tig.  361. 
a & 

“f 

0 

d 

Small  Bones  of  the  Ear.  a,  The 
the  Inner  (B)  Sides.  1,  Meinbrana  Tympani.  2,  Mai-  Malleus.  5,  The  Incus,  c,  The 
leus.  3,  Stapes.  4,  Incus.  Lenticular  Bone,  c?,  The  Stapes. 

required.  This  cavity  contains  the  little  bones  of  hearing/' 
as  they  are  sometimes  called.  These  are  the  Malleus,  a ham- 
mer,— the  Incus,  an  anvil, — and  the  Stapes,  a stirrup,  be- 
cause they  somewhat  resemble  these  instruments.  The  Mal- 
leus lies  directly  against  the  drum  of  the  ear  (Membrana 
Tympani),  its  opposite  side  connecting  Avith  the  Incus,  which 
is  in  connection  with  the  end  of  the  Stapes,  thus  forming  a 
continuous  chain  of  bones  through  the  Tympanic  Cavity.  In 
the  walls  of  the  Tympanum  are  no  les^  than  ten  opeinings, 
the  most  important  of  which  are,  one  downwards  into  the 
Pharynx  known  as  the  Eustachian  Tube,  another  into  the 
Labyrinth,  which  is  closed  by  the  foot  of  the  Stapes,  and  an- 
other outwards  to  the  External  Ear. 

717.  labyrinth. — Cochlea. — Semicircular  Canals  — 
Perilymph . — V e s t i b u 1 e . — The  Internal  Ear  is  called  a Laby- 
rinth because  of  its  very  complicated  structure  and  func- 
tions. (Fig.  362,  p.  392.)  It  mainly  consists  of  a series  of 
semicircular  canals  and  cavities,  of  which  some  are  made  up 
of  cartilage,  and  others  of  bone.  The  canals  are  composed  of 
bone,  three  in  number,  and  their  respective  planes  arranged  at 
right  angles  to  each  other.  They  contain  the  nerves  of  hear- 
ing and  other  substances,  Avhich  facilitate  the  transmission  of 
sound.  One  of  these  portions  is  named  the  Cochlea,  because 


What  are  the  names  of  the  bones  of  the  ear  ? How  many  openings  are  there  in  the 
tympanum  ? 717.  AVhat  is  the  labyrinth?  Of  what  is  it  mainly  made  up  ? 


392 


IIITCIICOCK’R  ANATOMY 


Fig.  3G2. 


A View  of  the  Labyrinth  and  Tympanum  of  the  Ear,  with  the  Bones  in  Situ,  highly 
magnified.  1,  Processus  Longus  of  the  Malleus.  2,  Its  Processus  Brevis.  3,  Its  Manu- 
brium. 4,  Its  Neck.  5,  Its  Head.  6,  Body  of  the  Incus.  7,  Its  Processus  Brevis.  8,  8, 
Its  Processus  Longus,  with  the  little  head  for  articulating  with  the  Stapes.  9,  The  Head 
of  the  Stapes.  10,  Its  Anterior  Crus.  11,  Its  Posterior  Crus.  12,  Its  Base.  13,  14,  15, 
The  first  turn  of  the  Cochlea.  16,  17,  IS,  Its  second  turn.  19,  Its  half  turn.  20,  The 
Cupola.  21,  The  Fenestra  Botunda.  22,  23,  The  Vestibule.  24,  25,  26,  Anterior  Semi- 
circular Canal.  27,  Its  junction  with  the  Posterior  Canal.  28,  29,  30,  31,  The  Posterior 
Semicircular  Canal.  32,  33,  34,  35,  The  External  Semicircular  Canal.  The  Enlargements 
on  these  Canals  are  called  Ampull®. 

it  resembles  a snail  shell,  and  some  of  the  others  semicircular 
canals,  because  they  are  tubes  containing  fluid  called  Peri- 

Fig.  363. 


Cochlea  without  the  Nerve. 


AND  PHYSIOLOGY. 


893 


lymph  and  nerve  fiber,  which  take  the  general  direction  of  a 
semicircle.  Of  these  cavities,  however,  the  cochlea  is  not 
filled  with  the  perilymph,  but  contains  the  finest  subdivisions 
of  the  auditory  nerve.  Besides  the  cochlea  and  semicircular 
canals  there  is  a small  three-cornered  cavity  called  the  Vesti- 
bule, into  which  the  five  openings  of  the  semicircular  canals 
enter. 

718.  Auditory  Nerve, — The  nerve  of  hearing  belongs  to 
the  eighth  pair  of  Cranial  nerves.  It  divides  into  two 
branches  just  before  it  enters  the  ear,  one  of  which  is  called 
the  cochlear  branch,  because  it  is  sent  to  the  cochlea,  and  an- 

Fig.  364. 


Auditory  Nerve  taken  out  of  the  Cochlea.  1, 1, 1,  Trunk  of  the  Nerve.  2,  2,  Its  fila- 
ments in  the  Zona  Ossea  of  the  Lamina  Spiralis.  3,  3,  Its  Anastomoses  in  the  Zona  Vesi- 
cularis. 

other  the  vestibular,  since  it  enters  the  vestibule,  a portion  of 
the  labyrinth.  Besides  this  a branch  of  the  facial  nerve  en- 
ters the  ear  in  company  with  the  auditory. 

719.  location  of  the  Internal  Ear.— Inman  and  all 
the  higher  animals  there  are  two  separate  organs  of  hearing. 


Describe  the  cochlea.  What  are  the  semicircular  canals  ? What  are  they  filled  with  ? 
718.  What  is  the  nerve  of  hearing  ? 719.  In  what  bone  is  the  ear  located  ? 


304 


HITCHCOCK’S  ANATOMY 


or  an  ear  upon  each  side  of  the  body,  and  no  internal  connec " 
tion  exists  between  them,  so  that  one  may  be  injured  or  de- 
stroyed while  the  other  performs  its  office.  In  fact,  the  inter- 
nal ear  is  protected  by  the  hardest  bone  (the  temporal)  in  the 
body,  and  is  inclosed  in  a bony  sac  to  which  the  only  opening 
of  any  considerable  size  is  that  of  the  auditory  canal. 


FUNCTIONS  OF  THE  EAR. 

720.  Functions  of  the  Pinna —The  object  of  the  pinna  is 
to  convey  sound  to  the  auditory  canal.  This  it  does  by  con- 
duction and  convection ; that  is,  it  acts  as  a funnel  to  collect 
the  vibrations  of  air  and  transmit  them  to  the  auditory  canal, 
and  also  conducts  sounds  by  means  of  its  own  substance  in 
the  same  manner  as  a stick  of  timber  conveys  the  sound  made 
by  the  scratching  of  a pin  to  its  opposite  extremity  with  great 
distinctness.  Hence  the  use  of  the  external  ear  is  to  collect 
sounds  from  as  large  a surface  as  possible,  and  concentrate 
them  at  the  small  end  of  a funnel,  so  as  to  increase  somewhat 
their  intensity.  The  probable  design  of  the  ridges  and  fur- 
rows upon  the  pinna  is  to  give  a greater  exposed  surface  to  it 
as  well  as  to  receive  vibrations  more  accurately  which  come 
in  various  directions. 

721.  Use  of  the  Auditory  Canal. — The  use  of  the  audi- 
tory canal  is  to  give  greater  intensity  to  the  sounds  collected 
by  the  external  ear.  This  can  be  illustrated  by  placing  a 
long  tube  close  to  the  ear,  while  another  person  speaks  at  the 
other  extremity.  The  voice  will  be  greatly  increased  in  in- 
tensity, because  every  vibration  is  transmitted  to  the  ear^  and 
none  are  dissipated  upon  the  air  or  surrounding  substances. 
Tlie  auditory  canal  performs  the  same  office,  although  in  a less 
degree  than  in  the  above  experiment.  This  canal  also  exists 

Is  tlicnj  any  coiiiiiHinlcation  between  tlio  two  ears?  720.  What  is  the  object  of  the 
j>inna?  How  <loe8  it  convey  sound  to  the  internal  ear?  Why  is  the  pinna  of  such  an 
uneven  surface  ? 721.  Of  wliut  servico  is  tho  auditory  canal  ? How  may  its  use  be  illus- 
trated ? 


AND  PHYSIOLOGY. 


895 


for  protection  to  the  membrana  tympani  and  the  delicate  or- 
gans of  the  ear,  which  must  be  placed  within  the  head  to 
such  a distance  that  no  harm  could  come  to  them  from  exter- 
nal violence. 

722.  Function  of  Membrana  Tympani — Use  of  the  ‘^Lit- 
tle Boiies.’^ — The  membrana  tympani  is  a very  thin  and  elas- 
tic membrane,  not  half  an  inch  in  diameter,  which  is  designed 
to  receive  all  the  vibrations  of  the  air  falling  upon  it.  On 
this  account  it  is  stretched  directly  across  the  auditory  canal, 
and  is  so  arranged  that  by  means  of  muscles  it  may  be  ren- 
dered more  or  less  tense,  so  that  if  it  is  desired  to  catch  a 
very  faint  sound,  the  drum  may  be  made  so  sensitive  as  to 
catch  the  slightest  vibration.  The  sound  received  by  the 
drum  of  the  ear  is  transmitted  to  the  auditory  nerve  by  means 
of  the  chain  of  bones  already  mentioned,  the  broad  side  of  the 
malleus  resting  directly  against  the  drum,  and  the  broad  end 
of  the  stapes  closing  the  opening  in  the  semicircular  canals 
which  contain  the  nerve  of  hearing.  The  use  of  this  arrange- 
ment seems  to  be  to  catch  all  the  vibrations  of  the  drum,  and 
instead  of  allowing  them  to  expend  themselves  upon  the  air 
in  the  tympanum,  to  transmit  them  directly  to  the  auditory 
nerve.  The  use  of  the  cavity  of  the  tympanum  seems  to  be 
to  allow  a free  vibration  of  the  membrane  of  the  drum.  An- 
other reason  for  the  large  size  of  the  tympanum  is  to  prevent 
the  conveyance  of  sound  to  any  other  part  of  the  ear  but  the 
semicircular  canals,  and  that  by  means  of  the  chain  of  little 
bones.  And  in  order  to  convey  the  sound  only  to  the  nerve 
of  hearing  the  stapes  joins  on  to  the  canal,  not  by  a solid  ar- 
ticulation, but  simply  by  cartilage,  so  that  none  of  the  vibra- 
tions can  be  conveyed  to  the  walls  of  the  canals,  but  all  to 
the  nerve. 

723.  Function  of  Eustachian  Tube.— The  design  of  the 


What  does  this  canal  protect?  722.  What  is  the  function  of  the  membrana  tympani  ? 
Of  what  use  are  the  “ little  bones  ?”  What  service  is  rendered  by  the  tympanum  ? How 
does  the  stapes  unite  with  the  canal  ? 


390 


HITCHCOCK’S  ANATOMY 


Eustachian  tube  is  evidently  to  allow  of  equal  atmospheric 
pressure  upon  both  sides  of  the  membrana  tympani.  For 
were  the  air  in  the  tympanum  closely  confined,  the  atmos{)hcre, 
varying  as  it  does  in  density,  would  sometimes  create  such  a 
pressure  on  the  drum  that  all  vibrations  would  be  indistinctly 
conveyed  to  the  brain.  This  is  the  same  arrangement  that  is 
found  in  bass  and  tenor  drums  used  for  musical  instruments, 
a small  orifice  always  being  necessary  to  give  free  access  to 
the  air.  Hence,  when  we  have  a cold,  or  especially  a sore 
throat,  where  the  mucous  membrane  is  inflamed,  we  often  find 
hearing  difiicult,  because  the  lining  membrane  of  the  Eus- 
tachian tube  is  so  much  swollen  that  air  can  not  pass  through. 
Also  when  the  same  condition  prevails  we  can,  by  swallowing 
the  small  amount  of  saliva  in  the  mouth  with  considerable 
force,  drive  so  much  air  into  the  tympanum  that  a sense  of 
fullness  occurs  in  the  ear,  which  continues  until  the  air  has 
found  some  means  of  escape. 

724.  Functions  of  the  Internal  Ear.— The  uses  of  all  the 
parts  belonging  to  the  internal  ear  are  not  perfectly  under- 
stood. Probably,  however,  the  labyrinth  and  cochlea  serve 
to  give  as  great  expansion  as  possible  to  the  nerve  in  the 
small  space  provided  for  it.  And  the  use  of  the  fluid  filling 
the  labyrinth  is  to  secure  all  the  vibrations  coming  in  through 
the  bones  of  hearing,  and  give  them  greater  intensity.  Some 
experiments  worked  out  by  Muller,  a German  physiologist, 
throw  considerable  light  on  the  subject.  He  found  that 
sounds  passing  directly  into  water  from  the  air  lose  consider- 
able of  their  intensity  ; but  if  a tense  membrane  is  placed  be- 
tween the  two,  greater  intensity  is  produced.  The  intensity 
is  also  greatly  increased  when  to  this  membrane  is  attached 
a small  solid  body  which  communicates  with  the  water  alone. 
This  seems  to  show  why  the  drum  receives  all  the  sound 


723.  What  is  the  use  of  the  Eustachian  tube  ? In  what  instruments  of  music  is  there 
u similar  arranf'cment?  Why  does  partial  deafness  sometimes  accompany  a cold?  724. 
What  is  said  of  the  functions  of  the  internal  ear  ? Relate  the  experiments  made  by 
Muller. 


AND  PHYSIOLOGY. 


397 


ratner  than  some  other  part  of  the  ear,  and  also  the  value  of 
the  three  small  bones  of  the  ear,  at  one  extremity  fastened  to 
the  drum  and  at  the  other  by  cartilages  to  the  semicircular 
canals.  Other  experiments  also  showed  that  a solid  body  of 
the  form  of  the  stapes  alone  was  the  best  to  communicate  with 
the  auditory  nerve. 

725.  Function  of  the  Cochlea  and  Semicircular  Canals, 
— It  has  been  thought  by  some  that  the  cochlea  enables  one 
to  determine  the  pitch  of  sound,  since  animals  which  possess 
the  fullest  development  of  this  organ  have  the  largest  range 
of  voice.  Another  speculation  is,  that  the  semicircular  canals 
aid  in  the  determination  of  the  direction  from  which  sounds 
come,  since  in  animals  where  they  exist,  they  are  always 
placed  at  right  angles  to  each  other. 

725  a.  Three  Physical  Properties  of  Sound— The  three 
physical  peculiarities  of  sound  are  intensity  or  loudness,  pitch 
or  length  of  the  waves,  and  quality,  or  the  difference  between 
the  same  note  on  a flute  and  violin,  although  equal  in  intensity 
and  pitch.  And  a theory  has  been  proposed,  substantiated  by 
many  facts,  that  the  membrana  tympani  enables  us  to  deter- 
mine the  intensity,  the  cochlea  the  pitch,  and  the  semicircular 
canals  the  quality  of  sound. 


THE  SENSE  OF  HEARING  IN  ANIMALS. 

726.  External  Ears — Semicircular  Canals— Cochlea — 
Os  (Iliad  rat  urn. — All  mammals,  as  a general  rule,  have  ex- 
ternal ears.  These,  in  some  animals,  like  the  bat,  are  enor- 
mously developed  in  proportion  to  the  dimensions  of  the  body. 
Besides,  in  several  genera  they  can  be  turned  in  any  direction 
the  animal  may  choose.  In  man  the  ear  consists  of  but  one 


725.  What  suggestion  has  been  made  of  the  use  of  the  cochlea  and  semicircular  canals? 
725  a.  What  are  the  three  physical  peculiarities  of  sound  ? 726.  What  mammals  have 
external  ears?  What  is  said  of  them  in  the  bat?  How  many  pieces  has  the  pinna  in 
most  animals  ? 


398 


HITCHCOCK’S  ANATOMY 


piece,  while  in  the  other  mammalia  it  consists  of  three.  But 
the  most  important  part  of  this  organ,  the  labyrinth,  agrees 
in  its  structure  throughout  tlie  whole  class.  The  greatest 
variation  that  exists  is  in  the  semicircular  canals  and  cochlea. 
In  the  cat  the  canals  form  the  segment  of  a circle,  while  in 
the  goat  they  furnish  a portion  of  an  ellipse,  and  in  the  horse 
a parabolic  curve.  The  cochlea  varies  in  the  number  of  its 
coils.  In  the  whale  and  dolphin  it  makes  but  one  and  a half 
turns  ; in  man  two  and  a half ; in  the  ornithorynchus  half  a 
coil  much  resembling  that  of  a bird  ; while  in  the  squirrel  it 
makes  nearly  four  turns.  No  physiological  effect  of  these 
variations  has  as  yet  been  given.  In  man  and  the  apes  the 
whole  cavity  of  the  tympanum  is  concealed  in  a portion  of 
the  temporal  bone,  but  in  all  other  mammals  we  find  a pecu- 
liar tympanic  bone  which  varies  exceedingly  in  the  different 
classes. 

727.  Ear  of  Birds. — There  are  but  few  birds  which  have 
any  thing  like  an  external  ear.  One  species  of  owl,  however, 
has  a membranous  concentric  fold  which  can  be  used  as  a 
valve.  Tlie  cochlea  has  the  form  of  an  obtuse  cone,  which  at 
its  extremity  swells  into  an  oval  tubercle.  The  tympanic 
cavity  communicates  with  cavities  in  the  cranial  bones,  which 
greatly  increases  the  resonance  of  sound,  in  the  same  manner 
as  the  sounding-board  in  the  piano,  or  the  main  body  of  a 
violin  or  violincello. 

728.  Hearing  in  Reptiles. — Although  reptiles  present  a 
more  imperfect  form  of  the  organ  of  hearing  than  mammals 
or  birds  yet  they  possess  the  tympanum,  a membrana  tym- 
pani,  and  a chain  of  ossicles  or  little  bones.  Also  a cochlea 
is  found,  which  is  most  fully  developed  in  crocodiles  and  formed 
almost  as  in  birds. 


IIow  do  tho  c.anuls  diffor  in  different  animals?  What  variation  in  tho  cochlea?  What 
Isthe  os  qiiadratnm?  727.  What  bird  has  external  ears?  What  is  said  of  the  cochlea 
In  birds?  Wliatdoes  tho  tymj)anuni  communicate  with?  What  is  the  use  of  this  ar. 
rau^jement  ? 72S.  What  is  said  of  tho  organs  of  hearing  in  reptiles  ? 


AND  PHYSIOLOGY. 


399 


729.  Hearing  of  Fishes. — Among  the  lowest  order  of 
fishes  the  organ  of  hearing  is  siraplj  a sac,  which  is  full  of  a 
fluid  that  contains  small  bones  or  bits  of  bones  called  otoliths, 
and  the  auditory  nerve  is  distributed  upon  its  walls.  In 
almost  all  fishes  there  is  a more  or  less  perfect  form  of  the 
semi-circular  canals.  In  some  fishes  the  swimming  bladder 
extends  to  membranous  spaces  in  the  cranium  which  are  in 
connection  with  an  auditory  apparatus. 

730.  Articulates. — Among  the  Crustaceans  hearing  has 
been  observed  only  among  the  Decapods.  The  sense  exists 
in  the  Arachnoids,  but  no  organ  has  been  found.  The  same 
is  true  of  Insects,  Annelids,  and  Helminths. 

731.  Molluscs . — Hearing  has  been  ascertained  in  Lamelli- 
branchiata.  In  Cephalophora  it  is  of  a low  grade : but  an 
auditory  nerve  and  organs  exist  in  the  Cephalopoda. 

732.  Radiates . — The  organ  of  hearing  exists  in  the  Polypi 
and  perhaps  the  Acalephs,  but  has  not  been  discovered  in 
the  other  Radiates. 


SENSE  OF  TOUCH. 

DEFINITIONS  AND  DESCRIPTIONS. 

733.  Location  of  the  Sense  of  Touch.— The  organ  of  touch, 
with  the  exception  of  the  upper  surface  of  the  tongue,  is  the 
skin.  This  in  some  parts  is  much  more  sensitive  than  in 


729.  Do  fishes  have  the  regular  organs  of  hearing?  What  organs  do  they  liave  in  a 
rudimentary  state  ? 730.  What  apparatus  of  hearing  do  articulates  possess  ? Do  they 
seem  to  hear  sounds?  731-732.  What  is  said  of  the  sense  of  sound  in  molluscs  and  rad- 
utes?  733.  Where  are  the  organs  of  touch  located? 


400 


HITCHCOCK’S  ANATOMY 


others,  since  some  portions  of  the  skin  arc  more  fully  crowded 
with  nerve  fibers  than  others.  We  are  conscious  of  resistance 
if  w^e  place  a substance  in  contact  with  any  part  of  the  body ; 
and  although  we  are  able  with  the  tips  of  the  fingers  to  tell, 
whether  a body,  which  is  pressed  on  them,  is  circular  or  rect- 
angular, yet  we  can  not  with  certainty  decide  the  same  thing, 
if  the  substance  be  pressed  upon  any  other  part  of  the  body. 

734.  The  Direct  Instruments  of  T o u c li —The  direct  in- 
struments of  sensation  are  minute  loops  of  nerve  fibers  from 
the  posterior  roots  of  the  Spinal  Column,  lying  in  the  true 


Nerves  of  Sensation  at  the  Extremity  of  the  Human  Thumb. 


skin,  which  are  covered  only  by  the  Epidermis,  as  is  seen  in 
Fig.  365.  These  nerves  of  sensation  are  never  known  to  ter- 
minate in  a free  extremity,  but  always  in  loops;  and  in  the 
hand  and  foot  are  associated  with  the  Pacinian  Corpuscles, 
described  under  the  nervous  system. 

735.  P a p i 1 1 ac. — Those 
parts  of  the  skin  which  are 
the  most  sensitive,  are  cov- 
ered with  minute  projections 
called  Papillae,  which  seem 
to  be  mere  elevations 
the  general  surface  of  the 

What  is  Bald  of  the  whole  cutaneous  surface  ? 734.  What  are  the  iinmediate  instru- 
ments of  touch?  How  do  the  sensitive  nerves  always  terminate?  735.  Describe  the 
]>ai>illu). 


Fig.  366. 


Papilla)  of  the  Palm  of  the  Hand. 


AND  PHYSIOLOGY. 


401 


skin,  in  which  are  found  the  loop  of  a nerve,  and  a blood- 
vessel with  some  cellular  tissue.  The  main  use  of  them  seems 
to  be  to  place  the  nerve  in  such  a position,  that  it  will  be  most 
easily  impressed  with  whatever  external  substances  it  may  be 
brought  into  contact. 


FUNCTIONS. 

736.  The  Superficial  Parts  of  the  Body  most 
abundantly  Supplied  with  Nerves. — The  parts  of  the 
body  lying  deep  beneath  the  skin,  are  but  sparingly  supplied 
with  nerves  of  sensation,  which  is  a great  comfort  to  those  un- 
fortunate persons  who  are  subjected  to  surgical  operations, 
since  the  most  painful  part  is  in  cutting  through  the  skin, 
which  is  the  quickest  part  of  the  operation.  This,  however, 
is  the  case  only  when  the  deep  parts  are  in  health  (including 
the  bones)  ; for  if  any  of  these  parts,  and  especially  the  bones 
and  ligaments,  are  diseased,  they  constitute  a source  of  the 
greatest  pain.  The  necessity  of  this  arrangement  is  obvious 
from  the  protection  which  the  surface  of  the  body  requires 
from  violence  and  heat.  Were  it  not  for  these  body-guards^ 
we  by  our  other  senses  should  seldom  know  when  friction  or 
heat  was  consuming  the  skin,  nor  when  cold  was  destroying 
its  vitality. 

737.  Value  of  this  Sense  to  the  Blind. — To  those  de- 
prived of  the  sense  of  vision,  this  sense  is  of  great  value,  since 
it  is  by  this  only  that  they  are  enabled  to  pursue  any  labor, 
or  instruct  and  please  themselves  by  raised  alphabets,  or 
play  upon  musical  instruments.  And  it  is  interesting,  not  to 
say  wonderful,  to  see  what  accuracy  is  acquired  by  the  blind 
in  detecting  true  from  spurious  coins,  or  in  distinguishing  the 
quality  of  cloth  by  feeling  alone.  It  is  said  on  good  author- 

What  is  the  function  of  the  papillre?  736.  Why  are  the  superficial  parts  of  the  body 
the  most  abundantly  supplied  with  sensitive  nerves  ? Why  does  the  skin  need  sensibil- 
ity? 737.  What  is  said  of  the  value  of  this  sense  to  the  blind?  What  examples  are 
mentioned  as  illustrating  its  extreme  acuteness  in  the  blind  ? 


402 


HITCHCOCK’S  anatomy 


itj,  that  one  blind  man  became  a botanist,  another  a con- 
cbologist,  and  another  a land  surveyor,  simply  by  the  aid  of 
touch. 

738.  Effect  of  Habit  on  location  of  Sensation. — 
Habit  has  a wonderful  power  in  the  location  of  sensations  on 
the  skin.  Thus  it  is  frequently  the  case,  after  an  amputation  of 
a limb,  that  the  patient  declares  that  he  feels  pain  in  the  re- 
moved portion.  This  is  owing  to  some  irritation  in  a fiber  or 
fibers  of  the  remaining  nerve  trunk,  which  were  originally 
sent  to  the  supposed  seat  of  the  pain,  and  from  habit  the  suf- 
ferer locates  it  in  the  removed  part.  Also  after  the  Talia- 
cotian  operation — which  consists  in  making  a new  nose  from 
the  skin  of  the  forehead, — if  the  nose  itches,  the  patient 
scratches  the  forehead  as  the  seat  of  the  irritation. 

739.  Insensibility  produced  by  a long  continued 
Action  of  some  painful  Stimulus.— It  is  sometimes  the 
case  that  the  nerves  are  rendered  insensible  by  the  moderate 
but  long  continued  action  of  some  painful  stimulus.  A com- 
plete insensibility  of  the  skin  may  be  produced,  so  that  the 
severest  surgical  operations  may  be  performed  without  pain, 
by  the  application  of  snow  and  salt  mixed  in  equal  portions. 
Heat  will  also  do  the  same  thing,  as  shown  by  the  following 
example.  A traveling  man  one  winter’s  evening  laid  him- 
self down  upon  the  platform  of  a lime  kiln,  placing  his  feet,  ^ 
probably  benumbed  by  the  cold,  upon  the  heap  of  stones 
newly  put  on  to  burn  through  the  night.  Sleep  overcame 
him  in  this  situation  : the  fire  gradually  rising  and  increasing, 
until  it  ignited  the  stones  upon  which  his  feet  were  placed. 
Lulled  by  the  warmth  the  man  slept  on ; the  fire  increased 
until  it  burned  one  foot  and  part  of  the  leg  above  the  ancle 
entirely  off,  consuming  that  part  so  effectually  that  a cinder- 
like fragment  Avas  alone  remaining,  and  still  the  Avretch  slept 
on,  and  in  this  state  Avas  found  by  the  kiln  man  in  the  morn- 


73*^.  AVliat  cfToct  hns  liahit  upon  localizing  our  sensations?  739.  How  may  insensibility 
bo  BomoUniea  broufjht  about  ? What  wonderful  example  ? 


AND  PHYSIOLOGY. 


403 


ing.  Insensible  to  any  pain,  and  ignorant  of  his  misfortune, 
he  attempted  to  rise  and  resume  his  journey,  but  missing  his 
shoe,  requested  to  have  it  found  : and  when  he  was  raised, 
putting  his  burnt  limb  to  the  ground  to  support  his  body,  the 
extremity  of  his  leg  bone — the  tibia — crumbled  into  frag- 
ments, having  been  calcined  into  lime.  Still  he  expressed  no 
sense  of  pain,  and.  probably  experienced  none,  from  the  grad- 
ual operation  of  the  fire,  and  his  own  torpidity  during  the 
hours  his  foot  was  consuming.’’ 


THE  SENSE  OF  TOUCH  IN  ANIMALS. 

740.  ‘^It  is  probable  that  among  the  lower  animals  the 
proportion  of  intuitive  perceptions  is  much  greater  than  in 
man ; whilst  on  the  other  hand  his  power  of  acquiring  per- 
ceptions is  much  greater  than  theirs.” 

741.  Touch  in  Mammals.— Cat,  Rabbit,  Elephant, 
Bat. — Among  Mammals  touch  ordinarily  depends  on  little 
projections  known  as  papillae,  which  contain  a loop  of  a sensi- 
tive nerve.  In  man  this  structure  is  principally  found  in  the 
tips  of  the  fingers,  but  in  the  Monkey  it  is  found  in  both  the 
hands  and  feet.  In  a majority  of  mammals  the  surface  of 
the  nose,  upper  lip,  and  the  vibrissae  or  whiskers,  as  seen 
on  the  face  of  the  cat,  are  organs  adapted  to  the  sense  of 
touch.  Cats  are  unable  to  catch  mice  when  these  whiskers 
are  removed,  and  Rabbits  without  the  assistance  of  their  eyes 
can  by  means  of  these  hairs  find  an  outlet  in  a very  narrow 
passage.  In  the  Elephant  this  sense  has  its  seat  at  the  ex- 
tremity of  the  proboscis.  The  wing  of  the  Bat  possesses  an 
extraordinary  sensitive  power.  It  is  said  that  this  animal  is 


T40.  What  is  said  of  the  intuitive  perceptions  of  the  lower  animals  ? T41.  Where  is 
the  sense  of  touch  most  perfectly  developed  in  a^nimals  ? Of  what  use  are  the  whiskers 
of  the  cat  and  rabbit  ? Where  is  the  sense  of  touch  in  the  elephant  ? 


404 


HITCHCOCK’S  ANATOMY 


able  to  fly  through  perfectly  dark  and  irregular  narrow  pas- 
sages, and  avoid  all  obstructions  simply  by  the  delicate  sensi- 
bility of  its  membranous  wings. 

742.  Touch  in  Birds. — The  only  portions  of  the  skin  in 
Birds,  on  which  tactile  papillae  exist,  are  found  on  the  under 
surface  of  the  foot,  and  the  web  of  the  web-footed  birds.  The 
bill  of  the  Duck  seems  also  to  subserve  the  sense  of  touch, 
upon  the  inside  of  which  the  skin  is  soft,  and  has  many 
branches  of  the  fifth  pair  of  nerves  distributed  to  it. 

743.  Touch  of  Reptiles. — The  sense  of  touch  seems  to 
exist  in  Reptiles,  though  the  prominent  use  of  the  skin  is  to 
afford  a protection  to  the  body.  It  is  quite  probable  that  the 
acuteness  of  this  sense  in  these  animals  is  no  greater  than 
what  is  derived  to  the  Horse  through  the  hoof,  or  to  a man 
through  a stick  or  rod  in  the  hand. 


744.  Touch  of  Fishes. — Fishes  probably  have  a still 
more  imperfect  sense  of  touch  than  Reptiles.  It  is  pos- 
sible that  the  lips  may  give  an  imperfect  idea  of  the  form 
of  external  objects;  but  the  surface  of  the  body,  covered 
as  it  is  with  scales  and  a thick  mucous  secretion,  can  be 
of  no  service  in  this  sense.  A few  fishes  have  hair-like 
appendages  about  the  head,  which  put  them  in  a condition 
to  be  acquainted  with  the  presence  of  external  objects,  though 
they  are  not  by  any  means  organs  of  active  touch. 

745.  Touch  of  Articulates. — This  sense  is  well  devel- 
oped in  all  the  Articulates,  and  shows  itself  especially  in  the 
antennae,  the  palpi,  and  feet ; and  though  these  organs  have 
a tough,  hair-like  consistence,  yet  they  are  efficient  instru- 


Wlierc  in  the  bat?  742.  Where  are  papillse  found  in  birds?  WTiat  answers  the  pur- 
pose of  papill»3  in  the  duck?  743.  What  is  said  of  the  sense  of  touch  in  reptiles?  744. 
Where  is  the  sense  of  touch  located  iu  fishes  ? 745.  Describe  the  sense  of  touch  in  articu- 
lates. 


AND  PHYSIOLOGY, 


405 


merits  of  sensation. 

“ For  just  as  a blind 
man  judges  of  the 
proximity  and  char- 
acter of  objects  by 
the  impressions  com- 
municated to  his  hand 
by  the  contact  of  his 
cane,  with  which  he 
examines  them,  so 
may  an  insect  or 
crustacean  receive 
sensory  impressions 
from  the  nerves  dis- 
tributed to  the  basal  joints  of  their  long  antenna0,  although 
the  organs  themselves  may  be  as  insensible  (or  rather  as  un- 
impressible)  as  the  stick.’’ 

746.  Touch  of  Molluscs. — The  sense  of  touch  in  this 
group  is  well  developed.  In  some  of  the  orders  the  organs 
are  from  two  to  four  contractile  tentacles  situated  upon  the 
head,  or  the  anterior  part  of  the  back.”  With  some  Gas- 
teropods  these  tentacles  are  hollow  and  button-like  at  tlieir 
extremity,  and  can  be  inverted  like  the  finger  of  a glove.’" 

747.  Touch  of  Ra(liates^ — ‘‘The  sense  of  touch  is  well 
developed  among  the  Echinoderms.”  It  exists  here  and 
among  other  Radiates  in  tentacles  or  feelers.  Besides  this, 
other  individual  Radiates  seem  to  possess  a sensitiveness  of 
the  whole  surface  of  the  body,  though  nerves  can  not  be  the 
agents  which  secure  this  sense  to  them. 

Is  it  by  an  active  touch  that  this  sensation  is  gained  by  articulates  ? 746,  Describe 
touch  in  molluscs.  747.  What  is  the  touch  of  radiates  ? 


Fig.  367. 


400 


niTon  cock’s  anatomy 


SENSE  OF  TASTE. 

DEFINITIONS  AND  DESCRIPTIONS. 


748.  Anatomy  of  the  Tong 
nentlj  the  organ  of  taste.  Its 
Fig.  368. 


10 


Front  View  of  the  Upper  Surface  of  the 
Tongue,  as  well  as  the  Palatine  Arch.  1, 
1,  Posterior  Lateral  Half  Arches,  with  the 
Palato- Pharyngeal  Muscles  and  Tonsils.  2» 
Epiglottic  Cartilage,  seen  from  before.  3, 
3,  Ligament  and  Mucous  Membrane,  ex- 
tending from  the  root  of  the  tongue  to  the 
base  of  the  Epiglottic  Cartilage.  4,  One 
of  the  Pouches  on  the  Side  of  the  Posterior 
Fia?nurn,  in  which  food  sometimes  lodges. 
6,  Foramen  Caecum.  6,  Papillaj  Capitatae 
scu  Maximae.  7,  The  white  point  at  the 
end  of  the  line,  and  all  like  it,  are  the  Pa- 
pillae Fungiformes.  8,  Side  of  the  Tongue 
and  lliigae  Transvers.'c  of  Albinus.  9,  Pa- 
idlhc  Filiformes.  10,  Point  of  the  Tongue. 


ne. — The  tongue  is  preCmi- 
principal  part  is  made  up  of 
muscular  fibers  which  run  in 
various  directions,  although 
they  run  in  similar  directions 
upon  the  opposite  halves  of 
this  organ.  The  tongue  is 
covered  with  a thick  mucous 
membrane,  which  contains  a 
large  number  of  papillae  simi- 
lar to  those  of  the  skin,  which 
are  of  three  kinds,  the  Filiform, 
Fungiform,  and  Circum  vallate. 
The  filiform  are  from  one 
thirty-sixth  to  one  eighth  of 
an  inch  long,  of  a conical 
shape,  and  are  most  abundant 
on  the  middle  portion  of  the 
tongue.  The  fungiform  are 
situated  upon  the  tip  and  sides 
of  the  tongue,  and  are  some- 
what smaller  than  the  filiform. 
The  circumvallate  are  from 
six  to  twelve  in  number,  and 
are  arranged  upon  the  base 
of  the  tongue  in  the  form  of 
the  letter  V,  the  apex  pointing 
downwards.  They  consist  of 
a central  round  papilla  flat- 


748.  Wliiit  Is  the  organ  of  taste  ? Of  what  is  it  made  up,  and  with  what  is  it  covered  ? 
Name  the  three  kind*  of  papilluj.  Describe  the  Uliform,  fungiform,  and  circumvallate. 


AND  PHYSIOLOGY. 


407 


tened  at  the  end,  one  twenty-fourth  to  one  twelfth  of  an  inch 
in  diameter,  with  a lower  uniform  wall  closely  surrounding 
the  papilla.  More  nerves  are  distributed  to  the  circumvallate 
than  to  either  of  the  other  forms  of  papillae.  At  its  lower  or 


posterior  extremity  the 
tongue  is  attached  to 
the  os  hyoides,  and  at 
its  lower  front  portion 
to  the  lower  jaw  by  the 
fraenum  or  bridle  of 
the  tongue  ; so  that  it 
is  left  free  to  move  ei- 
ther backwards  or  for- 
wards by  the  contrac- 
tion of  the  appropriate 
muscles. 


Fig.  369. 


One  of  the  smallest  Pai)illa3  of  the  Tongue  highly 
Magnified. 


749.  Blood-Vessels  of  this  Organ —A  great  quantity  of 
blood-vessels  are  distributed  to  this  organ,  as  can  be  seen  by 
looking  at  the  under  side  of  it,  as  well  as  by  the  free  flow  of 
blood  when  it  is  wounded. 

750.  Nerves  of  Taste. — Of  nerves  there  are  no  less  than 
three  large  branches  supplied  to  the  tongue  from  the  cranial 
group  : the  gustatory  or  proper  nerve  of  taste,  a branch  of 
the  fifth  pair  which  is  distributed  to  the  papillse  ; the  glosso- 
pharyngeal distributed  to  the  mucous  membrane,  being  both 
a nerve  of  motion  and  sensation  ; and  the  hypoglossal  distrib- 
uted to  the  muscles,  being  preeminently  a nerve  of  motion. 


FUNCTIONS. 

751.  Use  of  the  Numerous  Muscular  Fibers  in  the 
Tongue. — To  effect  the  numerous  movements  of  the  tongue  in 

Which  kind  receive  the  most  nerves  ? To  what  is  the  tongue  attached  by  its  lower 
extremity?  749.  What  proportion  of  blood  is  sent  to  this  organ?  750.  How  many  nerves 
• are  sent  to  the  tongue,  and  what  are  they  ? 

18 


408 


HITCHCOCK’S  ANATOMY 


mastication,  swallowing,  tasting,  articulation,  etc.,  it  is  neces- 
sary that  the  muscular  fibers  should  run  in  various  directions. 
That,  however,  which  is  commonly  known  as  the  tongue  is 
only  the  tip  of  it,  while  the  largest  portion  lies  in  the  front 
and  lower  portion  of  the  pharynx,  where  most  of  the  muscu- 
lar actions  are  performed. 

752.  Use  of  the  Papillae. — The  papillae  of  the  tongue,  as 
those  of  the  skin,  are  constructed  for  the  purpose  of  giving 
as  much  surface  of  nerve  to  be  exposed  as  possible,  leaving  it 
mostly  in  t' e form  of  a loop.  The  filiform  papillae  are  not 
the  seat  of  the  sense  of  taste  or  touch,  but  arc  analogous  to 
the  lingual  spines  of  lower  animals  (which  gives  such  rough- 
ness to  their  tongues),  which  aid  in  mastication  and  protec- 
tion of  the  tongue.  As  the  sense  of  touch  is  most  acute  at 
the  tip  of  the  tongue,  it  is  supposed  that  the  fungiform  papillm 
are  the  instruments  of  touch  to  the  tongue  ; and  as  we  acquire 
the  sense  of  taste  more  at  the  base  than  at  the  tip  of  the 
tongue,  and  as  the  nerves  are  more  abundant  and  finest  at  the 
circumvallate  papillae,  these  probably  administer  mainly  to  the 
sense  of  taste. 

753.  Object  of  this  Sense. — The  main  use  of  this  sense  is 
to  direct  us  in  the  choice  of  proper  articles  of  food,  and  by 
this  means  to  excite  the  flow  of  saliva  and  mucus,  to  aid  in 
digesting  food.  In  man,  however,  this  sense  would  be  an  un- 
safe guide,  since  this  alone  can  not  aid  us  to  distinguish  whole- 
some from  poisonous  food,  although  many  of  the  lower  animals 
seem  able  to  make  such  a distinction  by  this  sense  alone. 

754.  Effect  of  Education  on  Taste. — Taste  is  made  won- 
derfully acute  by  education.  Epicures  are  able  to  tell  the 
manner  in  which  game  was  killed,  the  spices  used  in  cooking 
it,  and  the  length  of  time  since  it  was  killed,  when  eating  it. 


Tr^l.  Why  aro  there  so  many  muscular  fibers  in  the  tongue?  Where  does  the  larger 
]»oi  tlon  of  this  organ  lie  ? 752.  Of  what  use  are  the  papilhe?  What  sensation  is  gained 

by  the  filiform  papilla;?  In  what  jiapillse  docs  the  sense  of  taste  mainly  exist?  753. 
What  is  the  use  of  this  sense?  Is  it  alone  a safe  guide  for  man?  754.  What  effect  has 
education  upon  taste?  (live  Instances. 


AND  PHYSIOLOGY. 


400 


Wine  tasters  can  readily  give  differences  in  the  age,  growth  of 
the  grape,  and  the  purity  of  wines,  that  to  ordinary  observers 
are  imperceptible. 

755.  Taste  as  Influenced  by  Smell.— Taste,  as  to  some 
substances,  is  dependent  on  the  sense  of  smell.  Thus,  with 
the  eyes  and  nostrils  closed,  if  an  aromatic  or  spicy  substance 
be  chewed  it  is  impossible  to  say  what  the  substance  is,  except 
that  it  is  pungent,  although  it  may  be  one  with  which  the  per- 
son is  well  acquainted.  Yet  smell  does  not  aid  us  in  deter- 
mining the  taste  of  acids,  alkalies,  or  salts. 

756.  After-Tastes. — An  important  point  connected  with 
this  sense  is  that  known  as  after-tastes.  Thus,  frequently 
after  eating  sweet  substances  a bitter  taste  is  left  in  the  mouth, 
and  when  bitter  substances  have  been  tasted  a pleasant  and 
sweet  taste  is  left  in  the  mouth.  This  subject  is  a matter  of 
great  importance  in  the  art  of  cookery. 


THE  SENSE  OF  TASTE  IN  ANIMALS. 

757.  Use  of  the  Conical  Papillae. — This  sense  is  in  aB 
animals  confined  to  the  tongue  and  inner  surface  of  the  mouth. 
The  sensation  received  from  the  sapid  body  is  gained  through 
the  papillae,  which  are  present  on  the  tongue  and  in  general 
structure  resemble  those  of  the  skin.  There  are  probably 
four  kinds  in  mammals,  those  upon  the  central  part  of  the 
tongue  often  being  conical,  hard,  and  even  horny,  and  those 
upon  the  back  part  fungiform,  or  soft  and  cup-shaped,  as  is 
seen  in  the  tongue  of  the  cat.  The  conical  papillae  seem  to 
act  the  part  of  a rasp,  especially  in  the  carnivorous  animals, 
in  order  to  remove  all  the  particles  of  meat  from  bones.  And 


755,  Give  the  connection  between  taste  and  smell.  756.  What  is  said  of  after-tastes  ? 
757.  How  many  kinds  of  papillae  in  most  mammals?  What  are  the  uses  of  the  conical 
papillae  to  meat-eating  animals?  How  powerful  an  instrument  do  these  at  times  consti- 
tute ? 


410 


HITCHCOCK’S  ANATOMY 


SO  efficient  are  these  that  tlie  skin  of  some  of  the  more  deli- 
cate animals  is  removed  simply  by  the  licking  of  the  tongue 
of  one  of  the  more  powerful  carnivora. 

758.  Tongue  of  Birds  — In  the  Woodpecker  and  Hum- 
ming-Bird.— In  birds  this  sense  is  very  feeble,  since  the 
tongue  is  destitute  of  sensitive  papillae,  and  is  often  of  a hard, 
horny  consistence,  designed  probably  more  for  the  means  of 
obtaining  food  than  of  judging  of  its  quality.  In  some  birds 
the  tongue  is  furnished  with  one  or  more  ossicles  for  the  pur- 
pose of  giving  stability  and  strength  to  it.  In  woodpeckers 
the  tongue  is  not  only  long,  slender,  and  stout,  but  it  is  armed 

Fig.  370. 


Tongue. 

Head  of  the  Woodpecker. 

with  appendages  like  barbs  on  either  side,  in  order  that  it  may 
be  thrust  into  narrow  crevices  in  trees,  to  pierce  and  hold  in- 
sects upon  which  it  lives.  (See  Fig.  370.)  Humming-birds 
have  tongues  very  slender  and  slit  at  the  apex,  so  that  both 
sides  can  be  formed  into  a sort  of  tube  by  curving  them  to- 
gether from  the  outside,  in  order  that  the  bird  may  suck 
up  the  nectar  of  flowers.  And  in  both  of  these  birds  the 
tongue  can  be  extended  for  a long  distance  in  front  of  the 
body. 

759.  Tongue  of  Reptiles — Chameleon.— The  tongue  of 
most  of  the  class  of  reptiles  seems  to  be  constructed  for  other 
purposes  than  that  of  taste.  Like  that  of  birds,  it  is  pro- 
vided with  one  or  more  lingual  (tongue)  bones,  and  is  desti- 


75^.  Ifow  is  it  with  the  sense  of  taste  in  birds  ? Describe  the  tongue  of  the  woodpecker. 
Wlmt  is  its  use  ? What  is  the  tongue  of  the  humming-bird  ? How  far  can  the  tongue 
!»<•  protruded  in  either  of  tlicso  animals  ? 759.  For  wdiat  purpose  is  the  tongue  of  rep- 
t 1 -s  ? 


AND  PHYSIOLOGY. 


411 


tute  generally  of  papillae.  In  some  of  this  class  it  is  hardly 
perceptible,  while  in  Serpents,  Toads  and  the  Chameleon,  it 
is  very  long  and  capable  of  rapid  motion.  In  Chameleons  and 
Serpents,  when  the  tongue  is  at  rest,  it  lies  in  a kind  of  sheath 
at  the  base  of  the  mouth.  That  of  the  latter  is  forked  at  its 
apex,  while  the  former  has  a concave  disk  at  its  point  covered 
by  a viscid  secretion,  which,  by  the  dexterity  of  the  animal, 
can  be  thrown  at  once  against  the  insects  flying  in  the  air, 
thus  securing  its  food.  In  this  case  also  the  tongue  seems 
longer  than  the  body  itself. 

Fig.  311.  • 


Tongue  of  Common  Fly.  or,  Lobes  of  Lingula.  5,  Portion  enclosing  the  Lancets 
formed  by  the  Metamorphosis  of  the  Maxilla,  c,  Maxillary  Palpi,  a,  Portion  of 
one  of  the  Metamorphosed  Tracheaj  enlarged. 


How  does  the  chameleon  obtain  his  insect  food?  7G0.  Have  fishes  any  tongue,  or  the 
sense  of  taste?  761.  How  well  is  this  organ  developed  in  some  of  the  lower  animals? 
762.  Describe  the  shape  of  the  nose.  Of  what  is  it  principally  composed  ? 


412 


II  I T C n C O C K ’ S ANATOMY 


760.  This  sense  in  fishes  appears  to  be  very  feeble.  “The 
part  named  tongue  in  them  consists  merely  of  the  anterior  ex- 
tremity of  the  tongue-bone  covered  by  mucous  membrane.” 
If  fishes  possess  this  sense,  the  palate  rather  than  the  tongue 
is  probably  its  seat. 

761.  Invertebrates. — Taste,  doubtless,  exists  in  all  the 
lower  animals  else  how  could  they  select  their  food  ? The 
seat  of  this  sense  is  not  always  discoverable,  as  can  be  done 
in  the  Cephalopoda.  But  the  sense  exists  in  all,  even  in  the 
Protozoa.  Fig.  371  exhibits  the  tongue  of  the  common  fly, 
which  is  doubtless  the  seat  of  this  sense. 


SENSE  OF  SMELL. 

DEFINITIONS  AND  DESCRIPTIONS. 

762.  Anatomy  of  the  Nose.— The  Nose uvhich  contains 
the  organs  of  smelling,  is  a triangular  pyramid  placed  upon 
the  face,  its  apex  connected  with  the  forehead,  and  its  base 
descending  nearly  to  a level  with  the  upper  lip.  It  is  prin- 
cipally made  up  of  bone  cartilage  and  integuments,  having  a 

thin  plate  of  bone  (the  vo- 
mer) and  cartilage  in  the 
middle  which  run  in  a verti- 
cal direction,  and  divide  the 
cavity  into  two  portions  called 
the  nostrils.  (Fig.  372.) 

A View  of  the  Cartilages  of  the  Nose. 
1,  The  Nasal  Bones.  2,  The  Cartilaginous 
Septum.  3,  The  Lateral  Cartilages.  4, 
The  Alar  Cartilages.  5,  The  Central  por- 
tions of  the  Alar  Cartilages  which  consti- 
tute the  Columns.  6.  The  Appendices  of 
the  Alar  Cartilage.  7,  The  Nostrils. 


AND  PHYSIOLOGY. 


413 


762  a.  Use  of  the  Bones. — Use  of  the  Cartilages, 
and  the  Glands  in  Integuments. — The  bones  are  the 
two  nasal,  which  give  form  to  the  base  of  the  nose,  and  fur- 
nish a firm  attachment  to  the  muscles.  The  cartilage  is  of 
use  to  give  form  to  the  nose,  while  its  elasticity  lessens  the 
efiects  of  injuries.  The  integument  or  skin  is  quite  thick 
upon  this  organ,  and  aids  the  cartilage  in  giving  form  to  it. 
It  contains  in  its  substance  small  glands,  which  secrete  an  oily 
matter  to  protect  the  nose  from  extremes  of  weather.  These 
glands  are  liable  to  retain  dust  and  other  impurities  in  their 
orifices,  forming  the  black  specks  on  the  nose. 

763.  Lined  with  Mucous  Membrane.— The  whole  cav- 
ity of  the  nostrils  is  lined  with  mucous  membrane,  which  is 
continuous  with  the  lining  membrane  of  the  fauces  or  throat, 
with  which  the  nostrils  are  in  communication. 

764.  Cavities  of  the 
Nostrils.  — Nerve  of 
Smelling . — The  cavities 
of  the  nostrils  are  very 
irregular,  since  upon  their 
own  outer  sides  are  found 
the  turbinal  bones  and 
a similar  scroll-like  por- 
tion from  the  ethmoid 
bone,  for  the  purpose  of 
giving  as  large  a surface 
as  possible  for  the  expan- 

A Vertical  Section  of  the  Middle  Part  of  the  Nasal  Fossae,  giving  a Posterior  View  of 
the  Arrangement  of  the  Ethmoidal  Cells,  etc.  1,  Anterior  Fossaj  of  the  Cranium.  2,  The 
same  covered  by  the  Dura  Mater.  8,  The  Dura  Mater  turned  up.  4,  Tlie  Crista  Galli 
of  the  Ethmoid  Bone.  5,  Its  Cribriform  Plate.  6,  Its  Nasal  Lamella.  7,  The  Middle 
Si>ongy  Bones.  8,  The  Ethmoidal  Cells.  9,  The  Os  Planum.  10,  Inferior  Spongy  Bone. 
11,  The  Vomer.  12,  Superior  Maxillary  Bone.  13,  Its  Union  with  the  Ethmoid.  14, 
Anterior  Parietes  of  the  Antrum  Highmoriauurn,  covered  by  its  Membrane.  15,  Its 
Fibrous  Layer  16,  Its  Mucous  Membrane.  17,  Palatine  Process  of  the  Superior  Maxil- 
lary Bone.  18,  Eoof  of  the  Mouth,  covered  by  the  Mucous  Membrane.  19,  Section  of 
this  Membrane.  A Bristle  is  seen  in  the  Orifice  of  the  Antrum  llighmorianum. 


762  a.  State  the  use  of  bone  and  cartilage  in  the  composition  of  the  nose.  Of  what  ser- 
vice are  the  little  glands  in  its  skin?  763.  What  are  the  nostrils  lined  with?  7G4.  De- 
scribe the  cavities  of  the  nostrils. 


FiU.  3*73. 


414 


HITCHCOCK’S  ANATOMY 


sion  of  the  nerve  of  smell,  and  at  the  same  time  furnishing  such 
an  arrangement,  that  the  air  containing  the  odor  can  be  readily 
drawn  over  it.  This  nerve  is  the  Olfactory  or  first  pair  of 
cranial  nerves,  which,  as  soon  as  it  reaches  the  nostrils,  is 
divided  into  a great  number  of  filaments,  and  these  are  dis- 
tributed upon  the  mucous  membrane — called  Pituitary — al- 
ready described.  The  fifth  pair  of  cranial  nerves  also  sends 
branches  to  this  membrane,  by  means  of  which  it  is  that 
sneezing  is  effected. 

765.  Smell  under  the  Control  of  the  AVill— The  sense 
of  smell  is  somewhat  under  the  control  of  the  will,  since  the 
air  containing  the  odoriferous  particles  can  be  carried  over  the 
nostrils  or  rejected  at  pleasure,  and  it  can  also  be  cultivated 
to  a great  extent,  although  some  persons  are  naturally  more 
sensitive  to  odors  than  others.  It  is  related  that  a gentleman 
who  had  a great  antipathy  to  cats,  could  tell  if  there  was  one 
in  the  next  room  by  smell  alone.  And  the  blind  boy  Mitchell 
always  formed  a favorable  or  unfavorable  impression  of  a 
stranger  by  this  sense. 


THE  SENSE  OF  SMELL  IN  ANIMALS. 

766.  The  sense  of  smell  is  most  perfectly  developed  in  air- 
breathing  animals,  although  many  which  live  in  the  water,  can 
distinguish  odors  or  scents  to  a considerable  distance. 

767.  Smell  in  Mammals. — In  Mammalia  the  mucous 
membrane  covering  the  turbinal  bones  is  supplied  with  ol- 
factive  nerves.  And  in  carnivorous  animals,  like  the  Lion 
and  Tiger,  these  bones  are  split  up  into  several  laminae,  giving 
them  arborescent  or  tree-shaped  forms,  so  that  the  membrane 


Why  arc  tho  turhlnulbonos  placed  hero  ? What  is  tho  nerve  of  smelling?  765.  To 
Avhat  extent  is  smell  under  tho  control  of  the  will  ? What  curious  facts  in  this  connec- 
Ihm  ? 760.  In  what  animals  is  this  sense  tho  most  perfectly  developed?  767.  Among 
what  matiitmils  do  we  find  this  sense  in  th-e  greatest  perfection?  What  peculiarity  in 
tho  turhinal  hones  in  tho  Hon  ? 


AND  I D YSIOLOGT. 


415 


may  be  expanded  over  as  great  a surface  as  possible.  The 
cavities  in  the  bones  of  the  face  and  skull  in  these  animals,  as 
well  as  also  the  Horse  and  Deer,  are  very  much  developed, 
and  all  the  mammalia,  except  the  Whale  tribe,  are  supplied 
with  a turbinal  bone,  the  cavities  of  which  are  lined  by  a 
membrane  which  greatly  aids  in  the  sense  of  smell.  The 
sense  of  smell  is  also  greatly  developed  in  the  timid  grazing 
animals,  so  that  they  may  in  this  way  receive  notice  of  the 
approach  of  their  enemies  and  escape.  For  most  quadrupeds 
give  off  a strong  odor  from  their  bodies,  in  the  exhalations  of 
the  skin. 

768.  Smell  in  Birds. — A Nasal  Gland. — Birds  possess 
turbinal  bones  and  a large  nasal  cavity,  but  it  is  doubted 
whether  much  of  the  power  of  discerning  their  prey  de- 
pends on  this  sense,  or  whether  it  does  not  entirely  depend 
on  vision.  For  the  olfactory  nerve  merely  ramifies  upon 
a part  of  the  nasal  cavity,  the  remaining  portion  being  sup- 
plied with  branches  from  the  fifth  pair.  There  is,  how- 
ever, a peculiar  gland  called  the  nasal,  which  serves  the  pur- 
pose of  lubricating  the  pituitary  (or  mucous)  membrane,  which 
is  probably  necessary  from  the  fact  that  so  much  air  is  con- 
stantly passing  over  the  nostrils  that  the  membrane  'would 
otherwise  become  dry  and  thus  impair  the  sense  of  smell. 

769.  Smell  in  Reptiles. — Reptiles  seem  by  their  organiza- 
tion of  very  simple  nasal  cavities,  to  have  their  sense  of  smell 
feebly  developed.  A few  only  have  bony  or  cartilaginous 
turbinal  organs,  and  a portion  only  have  the  cavities  lined 
by  a pituitary  membrane  ; and  from  the  gormandizing  habits 
of  these  animals,  we  see  that  the  sense  of  smell  could  be  of 
but  little  service  to  them. 

770.  Smell  in  Fishes. — Fishes  possess  a cavity  lined  by  a 


What  bone  is  the  whale  tribe  wanting  in  ? How  is  the  sense  of  smell  in  grazing  ani- 
mals? 768.  How  well  developed  are  the  organs  of  smell  in  birds?  What  is  probably  the 
case  with  regard  to  their  powers  of  smell  ? What  gland  is  furnished  to  them  which  pos- 
sibly aids  this  sense  ? 769.  What  is  said  of  this  sense  among  reptiles?  Is  this  sense  of 
any  great  value  to  them  ? 


18* 


416 


HITCHCOCK’S  A N A T O Y 


pituitary  membrane  and  furnished  with  olfactory  nerves,  which 
gives  them  a powerful  organ  of  smell.  This  cavity,  however, 
has  no  posterior  orifice,  its  only  opening  being  in  front,  and 
the  water  in  it  being  continually  kept  in  motion  by  the  cilim 
with  which  it  is  lined.  In  the  sharks  and  rays  there  is  a mus- 
cular appendage  to  keep  the  water  in  motion,  so  that  Sir 
Richard  Owen  says  these  animals  must  actively  scent  (that  is 
search  for  odoriferous  impressions)  as  well  as  smell. 

771.  Artie  Ilia  t a. — Crustaceans  have  the  sense  of  smell, 
and  the  central  ganglion  sends  off  an  olfactory  nerve.  The 
Arachnoids  can  smell  without  any  discoverable  organ.  So 
also  the  Insects.  Probably  all  of  the  Articulates  have  this 
sense,  but  perhaps  without  special  organs. 

772.  Molluscs . — In  Cephalopods  olfactory  organs  are  made 
out,  but  not  in  the  other  classes. 

773.  Radiata . — No  distinct  organs  for  this  sense  have  been 
found  in  these  animals.  But  the  presumption  is  that  it  exists 
with  or  without  special  organs  in  them  all. 

Of  the  Protozoa  the  Infusoria  clearly  evince  sensation  and 
volition ; but  no  nervous  system  has  been  discovered  in  them, 
and  though  it  is  quite  manifest  that  they  are  sensible  to  the 
contact  with  objects  and  to  light,  yet  there  is  no  evidence  that 
they  have  the  sense  of  smell.  Equally  probable  is  it  that  it 
is  wanting  in  the  Rhizophoda. 


HYGIENIC  INFERENCES  IN  RESPECT  TO  THE  SENSES. 

774. — 1.  Moderation  in  their  Use  Required. — All  the 
organs  of  sensation  require  to  be  moderately  employed.  If 


770.  How  Is  It  with  the  sense  of  smell  in  fishes?  What  peculiarity  amon»  the  sharks 
nnd  rays?  771.  Have  articulate  animals  the  power  of  smelling?  Have  they  the  organs 
a(lai>tc<l  to  it  ? How  is  it  probable  that  lobsters  smell  ? 772.  Can  shell-fish  smell  ? 773. 
What  of  animals  lower  in  the  scale  ? 


AND  PHYSIOLOGY. 


417 


the  eye  be  used  in  too  strong  light,  weakness  or  partial  pa- 
ralysis of  the  optic  nerve  may  be  produced ; and  if  the  ear 
receive  too  violent  a sound,  deafness  may  follow,  and  so  with 
the  other  senses.  Therefore  care  should  be  taken  in  the  use 
of  the  senses,  for  when  the  function  of  one  of  the  nerves 
of  special  sensation  is  gone,  it  is  very  rarely  if  ever  restored. 

775. — 2.  Sudden  Extremes  of  Sensations  to  be  Avoided. 
— With  some  of  the  senses,  and  especially  that  of  vision,  great 
care  must  be  taken  to  avoid,  if  possible,  sudden  transitions. 
Next  to  very  excessive  use  and  mechanical  violence,  no  greater 
trial  can  be  given  to  the  optic  nerve  than  a sudden  contact 
with  powerful  light.  To  a student  this  inference  is  of  great 
value,  and  especially  to  those  who  would  rise  early  and  study 
by  candle-light,  before  daybreak.  This  practice  is  often  a 
source  of  confirmed  weak  eyes.  One  reason  is,  that  during 
sleep  the  pupil  is  dilated,  and  when  the  eye  is  opened  does 
not  readily  contract.  This  statement,  however,  is  not  an  ar- 
gument against  early  rising,  which  for  other  reasons  has  been 
shown  to  be  healthy  to  the  student.  A good  rule  for  students 
in  sound  health  during  the  long  nights  of  the  year  is  to  rise 
before  daybreak,  and  after  washing  the  eyes  in  pure  cold  water 
to  take  a good  share  of  the  exercise  needed  for  the  day. 
Then,  after  an  early  breakfast,  when  food  and  exercise  are 
both  obtained,  he  maybe  ready  for  a day’s  work  of  hard  study 
by  the  congenial  light  of  the  sun.  If,  however,  circumstances 
are  such  that  we  must  study  in  the  morning  by  lamp-light, 
we  should  commence  and  work  moderately  until  the  eye  is 
accustomed  to  the  light. 

775.  a. — 3.  Cleanliness  of  the  Organs  of  Sensation  Nec- 
essary.— Perfection  of  sensation  requires  that  all  the  organs 
should  be  kept  clean.  The  eye  needs  occasional  washing,  not 


774.  Why  do  the  senses  all  require  moderation  in  their  use?  What  if  a nerve  of  special 
sense  is  destroyed  ? 775.  What  is  said  of  sudden  extremes  of  sensation  ? Why  should 
students  especially  avoid  all  extremes  of  light  and  darkness  as  far  as  possible  ? How  does 
early  rising  affect  the  eyes  ? 775.  a.  How  does  cleanliness  affect  all  the  organs  of  tho 
senses  ? 


418  HITCHCOCK’S  ANATOMY 

rubbing,  with  cold  water  ; the  ear  not  only  needs  the  applica- 
tion of  cold  water,  but  occasionally  the  careful  use  of  the  car- 
pick  to  remove  the  accumulations  of  wax  which  is  gathered 
beyond  the  reach  of  ordinary  washing.  If  the  nostrils  are 
buried  by  collections  of  snuflf,  how  can  we  expect  acuteness  in 
the  sense  of  smell  ? 

776.  — 4.  Senses  Need  Education. — The  senses  need  edu- 
cation. No  portions  of  the  body  show  so  well  the  good  effects 
of  discipline  and  practice  as  do  the  organs  of  sense.  The 
power  which,  by  training,  can  be  acquired  of  distinguishing 
the  faintest  shades  of  color,  the  slightest  discord  between  mu- 
sical tones,  and  of  the  quality  and  flavor  of  food  and  drinks 
by  the  smell  and  taste,  is  so  great  as  to  astonish  us. 

777.  — 5.  Is  Taste  a Proper  Guide  for  the  Appetite? — 
The  question  often  arises  whether  the  sense  of  taste  can  be 
considered  a safe  guide  for  the  appetite.  As  it  is  natural, 
some  maintain  that  it  should  always  be  gratified.  But  even 
if  originally  safe  to  follow,  how  often  has  it  been  perverted  by 
extravagant  diet,  and  is  at  the  time  in  a morbid  condition  from 
a perverted  state  of  the  body  ? If  such  be  the  case,  we  should 
be  on  our  guard  against  indulging  peculiar  appetites,  or  strange 
tastes.  But  in  some  cases,  of  which  the  physician  is  the  best 
judge,  it  may  be  safe  to  allow  a reasonable  indulgence  in  a 
desire  for  a peculiar  article  of  food  or  drink. 

778.  — 6.  Our  Senses  Sometimes  become  Sources  of  Mis- 
ery . — In  such  a world  as  this  our  senses,  especially  if  exqui- 
sitely cultivated,  often  become  inlets  of  keen  sufiering.  Ob- 
jects disgusting  to  the  soul  must  necessarily  obtrude  themselves 
upon  every  one.  Those  who  are  afflicted  with  a dainty  appe- 
tite and  are  very  nice  and  particular  as  to  their  food,  often 
suffer  acutely  ; while  he  who  has  learned  to  eat  only  that  he 
may  live,  instead  of  living  only  that  he  may  eat,  experiences 


770.  Do  tlio  senses  show  the  good  elFect  of  education  ? 777.  Is  taste  a sufficient  guide 
for  the  appetite  ? What  Is  said  of  peculiar  appetites  and  tastes  ? 778.  Do  our  senses  ever 
give  us  pain  ? In  what  way  does  a cultivated  taste  often  make  us  wretched? 


AND  PHYSIOLOGY. 


419 


gustatory  enjoyment  from  the  same  food  that  turns  the  stom- 
ach of  another.  True,  a taste  for  the  fine  arts  must  be  culti- 
vated, although  the  sensorium  will  thereby  be  subject  to  pain 
from  discords  in  sounds,  and  incongruities  in  colors  and  forms. 
But  in  respect  to  diet,  regimen  and  manners  it  is  hazardous 
to  cultivate  the  sensibilities  till  we  become  disgusted  with  al- 
most every  thing  we  meet,  and  make  ourselves  objects  of  ridi- 
cule for  our  peculiarities. 

779. — 7.  A higher  kind  of  Happiness  than  that  de- 
rived from  the  Senses. — Finally,  we  ought  to  remember  that 
enjoyment  gained  through  the  senses,  is  not  the  highest  kind  of 
happiness  for  man.  Though  it  be  all,  or  nearly  so,  which  the 
brute  can  enjoy,  yet  the  intellectual  and  moral  powers  of  man 
demand  of  him  the  control  of  his  sensual  desires,  and  a love 
for  that  which  is  far  higher  and  purer.  For  thus  will  all  his 
faculties  be  engaged  in  their  appropriate  sphere,  and  keep 
bright  till  the  end  of  life,  and  as  its  evening  shadows  steal 
upon  him,  they  will  find  him  not  full  of  disease  and  low  de- 
sires, but  peaceful  and  happy,  ready  to  make  a change  from 
bodily  to  spiritual  realities,  almost  without  a sigh  and  with 
exulting  anticipations. 


779.  Is  sensual  happiness  superseded  by  no  higher  enjoyment? 


CHAPTER 


NINTH. 


RELIGIOUS  INFERENCES  FROM  ANATOMY  AND 
PHYSIOLOGY. 

780.  Highest  Use  of  Science. — The  highest  and  most 
important  use  of  all  science,  is  its  religious  applications  : since 
these  are  eternal,  while  all  its  secular  bearings  are  only  tem- 
poral. 

781.  Religious  Value  of  Anatomy  and  Physiology. — 
Perhaps  no  sciences  are  so  prolific  of  religious  applications  as 
anatomy  and  physiology.  They  bear  especially  and  almost 
exclusively  upon  Natural  Religion. 

I.  PROOFS  OF  THE  EXISTENCE  OP  GOD. 

782.  The  argument  for  a Deity  from  marks  of  design  so 
obvious  in  nature,  derives  some  of  its  most  striking  examples 
from  anatomy  and  physiology. 

783.  The  Eye. — The  eye  has  often  been  quoted  as  a strik- 
ing instance.  Who  can  mistake  its  object?  And  when  we 
examine  its  structure,  we  see  how  admirably  adapted  all  the 
parts  are — the  coats,  the  media,  and  the  nerve — to  secure  this 
object.  And  it  is  done  far  more  perfectly  than  by  the  finest 
optical  instrument  of  man’s  construction. 

784.  The  Ear. — In  the  ear  we  have  another  example  al- 
most equally  striking,  except  that  the  special  object  of  some 
of  its  parts  is  not  so  obvious  as  in  the  eye. 

785.  Hands,  Lungs,  Heart,  etc.— We  might  say  the 
same  of  the  hands  and  the  feet,  the  lungs,  the  muscles,  the 


ANATOMY  AND  PHYSIOLOGY. 


421 


nerves  and  the  heart.  If  design  is  not  manifested  in  their 
construction,  it  is  diflScult  to  see  how  they  could  be  mani- 
fested. The  mechanical  arrangements  and  operations  of  the 
different  parts  of  the  system  teach  the  same  lesson. 

786.  Skeleton —Spinal  Column.— Take  the  bones  of  the 
skeleton  for  an  example.  How  admirably  are  these  arranged  as 
a solid  framework,  around  which  the  soft  parts  of  the  system 
may  be  built  up  ! The  vertebral  column  is  not  a single 
straight  tube,  as  our  wisdom  would  probably  think  to  be  the 
safest  and  best  as  a protection  to  the  spinal  cord  within,  but  it 
is  made  up  of  over  thirty  bones  separated  by  an  elastic  sub- 
stance, yet  locked  together  and  fastened  by  strong  ligaments, 
so  as  in  fact  to  be  stronger  than  a single  piece,  and  moreover 
it  is  made  somewhat  crooked,  so  that  it  will  yield  a little 
when  jarred,  and  thus  prevent  the  brain  from  being  injured. 

787.  Joints. — The  joints  too,  how  admirably  fitted  for  the 
manifold  movements  we  need  to  make ! How  securely  fastened 
together  by  numerous  strong  ligaments  ! How  much  more 
efiectually  lubricated  by  the  synovial  fluid  than  the  most  per- 
fect engine  of  human  construction  ! Then  again,  how  exactly 
fitted  to  the  parts  of  the  body,  in  which  they  are  placed,  are 
the  different  kinds  of  joints,  the  ball  and  socket,  the  hinge, 
the  sutures,  etc.  ! 

788.  Muscular  Arrangement.— Their  Mechanical  Dis- 
advantage, etc. — Contraction. — Perhaps  even  more  striking 
are  the  character,  position,  and  mode  of  action  of  the  muscles. 
Always  in  pairs,  except  where  a single  one  is  all  that  is  needed; 
being  antagonistic  only  where  antagonism  is  wanted ; being  thick 
where  great  strength  must  be  exerted,  or  some  cavity  must  be 
filled  to  produce  symmetry  of  form ; being  thin  where  wide 
surfaces  were  to  be  covered,  or  a proper  proportion  could  not 
be  secured  between  the  different  parts  of  the  body.  Then  how 
wonderful  that  the  great  mechanical  disadvantage,  at  which 
muscles  act,  which  at  first  sight  seems  so  obviously  a defect 


422 


HITCHCOCK’S  ANATOMY 


of  arrangement,  should  on  reflection  be  found  wisely  adapted 
to  our  wants  and  comfort.  The  mode  in  which  the  muscles 
act  by  mere  contraction,  is  the  simplest  possible ; yet  when  we 
inquire  how  this  is  effected,  we  find  ourselves  in  contact  with 
some  of  the  profoundest  and  most  diSicult  of  all  subjects : 
there  is  not  only  design,  but  unfathomable  wisdom  here. 

789.  Harmony  of  Chemical  and  Vital  Agencies.— The 
conjoint  operation  of  chemical  and  vital  agencies  in  building 
up  and  perfecting  the  system,  and  freeing  it  from  impurities, 
is  another  marked  example  of  design.  These  agencies,  the 
chemical  especially,  are  blind,  and  we  might  expect  that  they 
would  as  often  destroy  as  they  would  preserve.  But  though 
they  are  incessantly  at  work  all  over  the  system,  as  if  it  were 
a busy  laboratory,  in  building  up  the  tissues,  in  converting 
elements  into  immediate  principles,  and  in  separating  and 
casting  out  of  the  body  the  superfluous  and  deleterious  mate- 
rials, all  goes  right  till  Providence  permits  disease  or  accident 
to  disturb  the  harmony  between  vitality  and  chemistry,  and 
from  the  disastrous  effects  of  their  morbid  action,  we  learn 
how  wisely  ordered  was  their  healthy  operation. 

790.  Special  Arrangement  exhibiting  Design.— There 
are  some  special  contrivances  and  arrangements  in  the  animal 
frame,  which  strikingly  show  design,  because  it  looks  as  if 
the  Author  of  Nature  had  made  a modification  of  his  plan 
to  meet  exigencies.  Take  a few  examples. 

791.  looped  Muscles. — Look  at  the  looped  muscles. 
There  the  tendon  is  fastened  by  a loop,  in  order  that  the 
direction  of  the  force,  applied  in  contracting  the  muscle,  may 
be  more  or  less  changed,  made  in  some  instances,  as  in  the 
oblique  muscle  of  the  eye,  to  pull  in  an  opposite  direction ; 
or  at  right  angles,  as  when  the  digastric  muscle  draws  down 
the  chin. 


702.  Anastomosis  of  Blood-Vessels. — Then  there  is  the 
inosculation  of  the  blood-vessels.  How  obviously  this  is  in- 


AND  PHYSIOLOGY. 


423 


tended  as  a security,  when  some  of  the  blood-vessels  are 
wounded  and  can  not  transmit  the  blood.  It  then  seeks  those 
side  channels,  and  soon  they  so  enlarge  as  to  give  free  passage 
to  all  the  blood  that  is  needed,  even  though  a large  vessel  has 
been  closed.  If  man  had  constructed  a machine  with  such  an 
arrangement  we  should  have  been  sure  what  was  the  design. 
Why  doubt  the  same  in  respect  to  God’s  work  ? 

793.  Protection  of  Large  Vessels. — Again,  the  large 
blood-vessels  and  nerves  are  placed  deep  in  the  system,  and 
where  they  pass  by  prominent  joints,  grooves,  or  tubes,  are 
made  for  them ; or  where  one  side  of  a joint  is  exposed  to 
injury  and  the  other  comparatively  secure,  the  important  ves- 
sels are  grouped  together  on  the  less  exposed  side,  as  in  the 
groin  and  arm-pit. 

794.  Annular  ligaments. — Take,  for  another  example, 
the  annular  ligaments  around  the  wrist  and  ankle.  Who  can 
doubt  that  they  were  placed  there  to  prevent  the  tendons  of 
the  muscles  from  starting  out  of  their  places,  when  the  mus- 
cles are  strongly  contracted  and  the  feet  and  hands  bent  ? If 
so,  who  can  doubt  that  a Being  of  infinite  wisdom  devised  and 
executed  this  arrangement  ? 

795.  Nervous  Power . — But  all  this  wise  disposition  of  the 
parts  of  the  body  might  have  been  made  and  yet  the  whole 
have  been  useless,  had  not  some  vivifying  force  been  added. 
Therefore  the  nervous  system  was  contrived  and  incorporated 
with  every  part  of  the  body,  commencing  with  the  brain  and 
ramifying  to  all  the  extremities.  It  needed,  too,  a central 
power  to  direct  and  control  the  nervous  energy,  and  therefore 
the  mind,  an  immaterial  and  immortal  principle,  was  enthroned 
in  the  brain.  From  thence,  as  along  so  many  conducting 
wires,  and  doubtless  by  means  of  galvanic  agency,  it  sends  out 
its  orders  to  originate  and  control  every  muscular  movement 
and  keep  in  play  every  function  of  the  body.  The  nervous 
system,  then,  is  the  mysterious  connecting  link  between  mind 
and  matter,  and  the  admirable  manner  in  which  it  performs  its 


424 


HITCHCOCK’S  ANATOMY 


functions  and  enables  the  thinking  principle  to  manifest  its- 
astonishing  powers,  shows  the  nervous  system  to  be  the  most 
wonderful  of  all  the  contrivances  which  Infinite  Wisdom  has 
placed  in  the  human  body.  What  could  demand  an  Infinite 
Deity  if  such  a contrivance  did  not  ? 

796.  Dependencies  of  one  System  upon  Ano the r— The 
connection  between  mind  and  body,  however,  is  only  imper- 
fectly understood,  and  therefore  there  is  one  other  thing  which 
exhibits  more  impressively  than  the  nervous  system  and  the 
mental  powers  the  agency  of  an  infinitely  wise  Being.  The 
human  body  is  made  up  of  quite  a number  of  minor  wsystems 
of  organizations  apparently  independent  of  one  another,  yet 
all  in  fact  mutually  dependent  and  combined  into  one  complete 
and  perfect  system,  with  the  parts  all  exactly  adapted  to  one 
another.  Could  any  thing  less  than  Infinite  Wisdom  have 
accomplished  so  marvellous  a work  ? 

797.  The  same  Plan  Exhibited  in  the  whole  Animal 
Kingdom . — Yet  if  we  extend  our  researches  through  the  whole 
animal  kingdom,  we  shall  find  that  this  same  mutual  adapta- 
tion and  correlation  extend  through  the  whole  series,  so  that 
all  are  but  parts  of  a mighty  whole.  From  man  downwards 
through  the  hundreds  of  thousands  of  species,  to  the  humblest 
animalcule,  each  occupies  a fitting  place,  and  every  link  of 
the  long  chain  is  in  perfect  harmony  with  all  the  rest,  so  that 
the  skillful  anatomist,  knowing  one  part  of  the  chain,  can 
delineate  the  rest,  just  as  a single  bone  of  an  animal  often 
determines  the  character  of  its  whole  frame.  What  vast 
reaches  of  thought,  what  wonders  of  wisdom,  what  boundless- 
ness of  power  must  it  have  required,  to  weave  together  so  vast 
and  varied  a system  into  one  golden  web  of  harmonies  ! 


II.  PROOFS  OF  DIVINE  BENEVOLENCE 

798.  All  Orgiins  (iiid  Finidions  Normally  Produce 
Happiness. — One  proof  of  Divine  benevolence  is,  that  all  the 


AND  PHYSIOLOGY. 


425 


organs  and  their  functions  are  adapted  to  promote  the  welfare 
of  the  individual.  They  may  incidentally  result  in  evil ; but 
the  object  was  to  produce  happiness.  One  object  of  the  ner- 
vous system  was  to  guard  us  against  injuries  by  putting  us 
on  our  guard  against  them.  But  in  case  of  injury  or  diseased 
action,  intense*  suffering  often  results  ; and  while  enduring  it 
we  are  apt  to  forget  the  grand  object  of  the  nerves  of  sensa- 
tion, and  imagine  incidental  to  be  intentional  evil.  So  carni- 
vorous teeth  and  poison  fangs  are  intended  to  provide  animals 
with  food  and  the  means  of  defense.  But  they  may  produce 
great  incidental  evils  by  being  used  as  animals  have  the  power 
to  do,  and  are  sometimes  incited  to  do,  aside  from  the  normal 
objects  for  which  they  were  given.  Indeed  there  is  no  organ 
or  operation  whose  leading  object  is  not  the  production  of  hap- 
piness ; and  therefore  we  infer  the  predominant  disposition  of 
the  Author  of  nature  to  be  benevolent. 

799.  Pleasure  Superadded  to  Functions  when  not  Re- 
quired.— A second  fact  leading  to  the  same  conclusion  is,  that 
often  pleasure  is  superadded  to  animal  functions,  when  it  is 
unnecessary  to  their  perfect  performance.  It  was  not  neces- 
sary to  perfect  vision  that  the  colors  in  nature  should  be 
agreeable ; that  the  earth,  for  instance,  should  be  green,  or 
that  colors  in  flowers  should  be  harmoniously  blended.  It 
was  not  necessary  for  the  support  of  the  system  that  gusta- 
tory enjoyment  should  accompany  the  reception  of  food ; for 
severe  hunger  would  have  been  sufficient  to  impel  us  to  eat, 
even  though  suffering  followed.  And  so  in  a thousand  other 
instances  that  might  be  named.  On  the  other  hand,  no  exam- 
ple can  be  founi  where  unnecessary  pain  attends  functional 
operations.  The  Author  of  such  a system  must  be  benevolent. 

800.  More  Modes  than  One  Provided  for  the  same  Func- 
tions . — A third  evidence  of  benevolent  design  in  the  Author 
of  the  animal  system  is  the  provision  often  made  of  more  than 
one  mode  for  the  performance  of  important  functions.  In  the 
act  of  swallowing,  for  instance,  the  danger  is  great  that  par- 


426 


HITCHCOCK’S  ANATOMY 


tides  of  food  may  pass  into  the  lungs.  Hence  not  only  is  the 
epiglottis  provided  to  close  upon  the  glottis  like  a valve  hy 
the  very  movement  that  carries  down  the  food  ; but  the  glottis 
itself  is  endowed  with  such  extreme  sensibility  that  it  instantly 
closes  upon  the  approach  of  a foreign  body.  The  inosculation 
of  the  blood-vessels  has  already  been  described,  furnishing  a 
double  means  of  circulation  as  a resort  when  one  fails.  We 
might  also  refer  to  the  two  cerebral  hemispheres,  two  lobes  to 
the  lungs,  two  eyes,  two  hands,  and  two  feet,  so  that  the  loss 
of  one  does  not  obliterate  the  function.  All  this  certainly 
looks  like  the  benevolent  provision  of  a kind  parent. 

801.  Surplus  or  Reserve  Power— And  so,  in  the  fourth 
place,  does  the  surplus  power  given  to  the  organs  for  exigen- 
cies above  what  is  necessary  exhibit  benevolence.  In  the 
muscles  there  seems  to  be  no  limit  to  this  excess  of  force,  save 
in  the  ability  of  the  fibers  to  endure  the  strain.  The  digestive 
organs  are  capable  of  mastering  a much  larger  amount  of  food 
than  is  necessary,  and  the  secretory  organs  at  times  give  out 
a much  larger  than  the  normal  quantity  of  their  peculiar  prod- 
ucts. If  it  were  not  so,  life  would  be  sacrificed  in  thousands 
of  instances  where  now  the  use  of  the  surplus  power  preserves 
it.  If  God  is  not  benevolent  how  happens  it  that  this  special 
provision  for  exigencies  should  always  promote  the  welfare  of 
animals  ? 

802.  Vicarious  Power. — In  the  fifth  place,  the  vicarious 
power  given  to  some  of  the  organs  teaches  the  same  lesson. 
When  one  or  more  of  the  senses  is  destroyed  or  defective,  the 
others  can  often,  in  a good  measure,  supply  their  place  : 
touch,  for  instance,  the  place  of  seeing  and  hearing.  So, 
also,  it  is  said  when  the  glands  appropriated  to  certain  secre- 
tions are  injured  or  destroyed,  others  whose  normal  secretion 
is  ({uite  different,  can  elaborate  the  principles  ordinarily  given 
out  by  the  injured  ones. 

803.  Adaptaliou  of  Organs  to  Different  Circumstances. 
— The  power  of  all  the  organs  to  adapt  themselves  to  different 


AND  PHYSIOLOGY. 


427 


circumstances  is  a sixth  example  of  benevolent  intention  in  the 
Author  of  nature.  The  range  of  this  power  is  limited  ; and 
yet  we  are  often  surprised  to  what  widely  different  conditions 
we  can  be  accustomed,  and  yet  be  comfortable  in  them  by  new 
habits.  In  such  a changing  world  as  this  is,  such  a power 
seems  almost  indispensable,  and  yet  only  infinite  skill  could 
attach  it  to  organs  which  are  controlled  by  inflexible  chem- 
ical and  vital  laws.  Malevolence  surely  never  would  have  be- 
stowed it. 

804.  Recuperative  Power. — The  recuperative  power  of 
the  animal  system  furnishes  us  with  a seventh  example  of 
benevolent  provision  by  the  Creator.  However  deeply  acci- 
dent or  disease  may  have  affected  the  system,  if  the  vital  pow- 
ers be  not  destroyed,  it  is  possible  frequently  to  bring  it  back 
again  to  a state  as  sound  and  vigorous  as  before.  The  records 
of  pathology  and  surgery  furnish  most  astonishing  cases  of 
such  restorations.  And  since  accident  and  disease  are  so  com- 
mon, that  scarcely  any  adult  can  boast  of  immunity  from 
them,  what  a sad  picture  would  society  present  of  cripples  and 
invalids,  were  this  recuperative  power  wanting.  It  would  be 
just  such  a picture  as  infinite  malevolence  would  delight  in. 
Its  opposite  therefore  indicates  benevolence. 

805.  Prospective  Benevolence. — One  other  example  only 
will  be  given,  and  that  may  be  called  prospective  benevolence. 
Wasps  and  some  other  insects  have  an  instinct  which  leads 
them  to  deposit  along  with  their  eggs  a supply  of  food  for  the 
young  insects  when  they  are  hatched,  sufficient  to  nourish 
them  till  they  are  old  enough  to  take  care  of  themselves.  In 
other  animals  nature  provides  a supply  of  milk  to  be  ready 
just  at  the  time  when  needed  by  the  progeny.  The  adulfc 
man  needs  a firmer  set  of  teeth  than  the  infant,  and  so  the 
germs  of  these  are  placed  beneath  the  earlier  teeth,  and  these 
at  the  proper  time  push  their  way  upward,  and  crowd  the 
first  set  out  of  their  sockets.  In  such  cases  the  wants  of 
animals  were  anticipated  by  their  Creator,  just  as  a be- 


42S 


niTC  II  COCK’S  ANATO]MY 


nevolent  parent  provides  beforehand  for  the  future  needs  and 
happiness  of  his  children. 

806.  — III.  ANATOMY  AND  PHYSIOLOGY  FURNISH  PRE- 
SUMPTIVE EVIDENCE  THAT  THE  WORLD  IS  IN  A FALLEN 
CONDITION. 

807.  Benevolence  blended  with  Pain. — We  have  shown 
that  benevolence  decidedly  predominates  in  all  the  organi^- 
tion  and  functions  of  the  animal  system.  But  it  is  not  un- 
mixed benevolence,  as  we  shall  now  attempt  to  show.  There 
are  evils  connected  with  our  physical  condition,  such  as  wo 
can  not  suppose  would  exist  in  a paradisaical  state,  and  the 
inference  is  that  these  evils  are  best  accounted  for  by  the  sup- 
position that  the  world  is  adapted  rather  for  a fallen  than  for 
a holy  being.  Let  us  look  at  some  examples  of  evils  which 
we  can  not  suppose  a Being  of  Infinite  Benevolence  and 
Power  would  connect  wdth  a state  of  perfect  holiness. 

808.  The  Nerves  much  more  Sensitive  than  is  neces- 
sary to  Protect. — 1.  The  nervous  system  produces  sufiering 
far  beyond  what  is  necessary,  to  put  us  on  our  guard  against 
accidents  and  injurious  agents.  To  awaken  and  cultivate 
such  prudence  in  respect  to  these  evils,  seems  obviously  a 
leading  object  of  pain  and  sufiering : for  the  nerves  are  most 
abundant  and  sensitive  at  the  surface  of  the  body.  But  in 
many  diseases  the  sufiering  is  intense.  Indeed,  exasperated 
and  maddened  nerves  produce  the  very  climax  of  human 
anguish.  But  some  other  object  besides  awakening  a salu- 
tary caution  against  evil  must  be  in  view  by  such  sufiering. 
Now  we  know,  that  as  a matter  of  discipline  for  a depraved 
and  sinful  being,  it  is  eminently  salutary.  It  afibrds  there- 
fore a presumptive  proof  that  such  is  man’s  character. 

809.  Impossibility  of  avoiding  Accidents  and  Disease, 
— 2.  Man’s  exposure  to  accidents  and  diseases,  which  no 
human  foresight  can  avoid,  leads  to  the  same  conclusion. 


AND  PHYSIOLOGY. 


429 


810.  That  he  is  thus  liable,  we  need  not  attempt  to  prove, 
because  all  will  acknowledge  it.  But  why  should  he  be  so 
exposed  under  the  government  of  a Being  of  Infinite  Benevo- 
lence, if  there  were  not  something  in  his  character  which  de- 
manded this  severity  of  discipline  ? What  can  that  be  but  an 
alienated,  rebellious  heart,  which  no  milder  means  will  subdue? 

811.  Evil  incidental  to  every  Function. — 3.  Evil  is 
incidental  to  the  functions  of  every  organ  in  the  body.  Vision 
exposes  us  to  be  witnesses  of  many  most  unpleasant  scenes 
and  objects,  hearing  to  sounds  most  grating,  taste  and  smell 
to  odors  and  solids  disgusting  and  poisonous ; locomotion 
makes  us  liable  to  fatigue  and  bodily  injuries,  and  disease  es- 
pecially assails  every  organ.  We  can  not  conceive  these  in- 
cidental evils  to  be  necessary  in  a world  of  perfect  purity  and 
happiness.  But  they  are  wisely  adapted  to  a fallen  being,  and 
therefore  the  presumption  is  that  man  is  in  such  a fallen  state. 

812.  — Universality  of  Death.— 4.  The  existence  and  uni- 
versality of  death  lead  to  the  same  conclusion. 

813.  It  may  indeed  be  made  probable  that  in  such  a state 
of  things  as  the  present,  death  is  a blessing  even  to  the  inferior 
creatures.  But  it  would  not  be  so  in  an  unfallen  paradisaical 
state.  It  must  be  an  immense  drawback  from  the  happiness 
of  such  a state.  It  is,  however,  a fit  and  probably  an  inevit- 
able concomitant  and  consequence  of  sin.  Where  it  is  uni- 
versal, therefore,  the  presumption  is  that  it  is  a fallen  state. 

814.  Condition  of  Man  not  without  Bright  Prospects. 
— 5.  But  though  anatomy  and  physiology  present  so  many 
proofs  of  man’s  fallen  condition,  yet  the  evidence  already  ad- 
duced that  benevolence  vastly  predominates,  affords  to  the 
student  of  natural  theology  a strong  presumption  that  it  is 
not  a hopeless  condition.  For  if  there  was  no  such  thing  as 
recovery,  why  so  many  tokens  of  kindness  ? Why  not  give 
up  the  offender  at  once  into  the  hands  of  justice,  and  let  the 
work  of  retribution  commence  ? How  the  recovery  might  bo 
effected  revelation  alone  could  show. 


II  ITC1  It  COCK’S  ANATOMY 


4r,o 


Objection,’— It  is  said  that  these  arguments  would  prove  the  Inferior  animals,  even  those 
that  lived  long  before  man,  to  be  in  a fallen  condition,  since  they  both  suffer  and  die. 

Answer. — The  lower  animals,  not  having  a moral  nature,  cannot  sin ; but  they  may 
suffer  in  consequence  of  their  connection  with  sinful  man.  The  world,  from  the  beginning, 
was  adapted  to  him  as  a fallen  being,  and  of  course  all  other  animals  must  be  subject, 
like  him,  to  suffering  and  death.  This  sympathy  of  all  nature  with  man's  fallen  condition 
is  clearly  taught  in  Revelation.  (See  Rom.  viii.,  18-23.) 

815. — IV.  ANATOMY  AND  PHYSIOLOGY  FURNISH  PROOF  OP 
THE  DIVINE  UNITY. 

That  is,  they  show  that  only  one  Mind  could  have  been 
concerned  in  the  plan  of  animal  organization. 

816.  — 1.  The  Conspiration  of  all  the  Parts  to  Produce 
the  Same  End. — This  appears,  in  the  first  place,  from  the 
conspiration  of  all  the  tissues  and  organs  to  produce  a single 
result.  There  are  as  many  as  a million  of  parts  in  the  hu- 
man body,  all  of  which  must  go  right  to  keep  the  system  in  a 
healthy  state.  It  may  worry  us  when  some  of  them  go  wrong, 
as  in  case  of  disease  ; but  if  many  of  them  become  deranged 
death  ensues.  An  attentive  observer  of  the  race  will  see  that 
all  these  parts  are  originally  arranged  so  as  to  conspire  in  the 
production  of  health  and  happiness. . There  could  have  been 
no  divided  counsels  in  such  a work. 

817.  — 2.  Relations  of  Different  Individuals  in  the 
Animal  Kingdom.— The  relations  of  all  the  branches  and  even 
individuals  of  the  whole  animal  kingdom  to  one  another  af- 
ford a still  more  striking  evidence  of  divine  unity.  For  here 
the  objects  to  be  compared  are  multiplied  a thousand  fold,  and 
the  extremes  in  organization,  in  habits,  and  modes  of  living 
are  immeasurably  wide.  Yet  there  is  such  a relation  among 
them  all  as  to  show  them  all  belonging  to  one  system,  bound 
together  in  the  closest  harmony.  All  must,  therefore,  have 
been  the  work  of  one  Infinite  Mind.  Or  if  more  than  one 
was  concerned,  each  must  have  had  the  same  plan  ; and  the 
idea  is  absurd  that  there  can  exist  more  than  one  infinite 
mind. 


AKB  PHYSIOLOGT, 


431 


S18. — V.  ANATOMY  AND  PHYSIOLOGY  DISPROVE  THE  ATHE- 
ISTIC HYPOTHESIS  THAT  THE  DEVELOPMENT  OF  ANIMAL 
ORGANS  IS  THE  RESULT  OP  MERE  LAW. 

819.  The  Development  Hypothesis, — This  hypothesis  sup- 
poses that  the  organs  were  not  contrived  and  constructed  by 
an  intelligent  mind  for  the  uses  to  which  they  are  applied,  but 
that  the  wants  of  the  living  mass  of  almost  amorphous  matter 
led  to  such  efforts  as  ultimately  to  form  an  organ.  Thus  the 
desire  for  food  in  a mass  of  vitalized  jelly  caused  it  to  pro- 
trude certain  points  which  ultimately  became  hands,  and  the 
desire  of  locomotion  formed  the  feet  and  legs.  To  form  the 
organs  in  this  manner  it  would  be  necessary  that  the  use  of 
parts  of  the  living  unorganized  mass  or  body  should  have  a 
natural  tendency  to  produce  them.  If  then  we  can  show  that 
in  some  cases  this  tendency  would  be  e^Tactly  the  opposite,  the 
hypothesis  must  fall.  We  need  give  only  a few  examples  to 
show  that  such  is  the  case.  Take  the  looped  muscles,  such  as 
those  in  the  back  of  the  eye.  Any  effort  of  matter  behind  the 
eye  to  move  the  ball  must  draw  in  a direct  line,  not  in  the 
round  about  course  of  a loop  attached  to  the  orbit.  Take  the 
case  of  the  annular  ligaments  at  the  wrist  and  ankle.  The 
conatus  of  the  muscles  to  move  the  fingers  and  toes  would 
tend  to  destroy  but  not  to  form  such  a ligament.  They  are  as 
obviously  intended  as  any  thing  can  be  to  counteract  the  con- 
atus of  the  tendons  to  fly  off  when  the  muscles  contract. 

820.  Such  facts  so  manifestly  show  the  absurdity  of  the 
hypothesis  under  consideration,  that^  examples  need  not  be 
multiplied.  It  is  true  of  nine  tenths  of  the  organs,  that  an 
effort  of  vitality  to  perform  their  functions  before  their  exists 
ence  would  have  a tendency  the  opposite  of  their  formation. 

19 


432 


HITCHCOCK’S  ANATOMY 


821. — VI.  ANATOMY  AND  PHYSIOLOGY  SHOW  THE  UNREA- 
SONABLENESS OF  OBJECTING  TO  MYSTERY  IN  RELIGION. 

822.  Any  objection  against  religion  that  will  lie  with  equal 
force  against  the  constitution  and  course  of  nature  is  futile. 
For  none  but  the  atheist  will  deny  that  nature  is  the  work  of 
God,  and  it  is  not  reasonable  to  object  to  that  in  religion 
which  we  allow  to  exist  in  nature.  But  the  cases  of  mystery 
in  anatomy  and  physiology  are  more  striking  than  in  religion. 
A few  examples  will  suffice. 

823.  — 1.  Muscular  movement.  We  can  see  that  muscles 
contract,  but  the  power  that  does  it  is  concealed.  We  find 
that  this  power  comes  from  the  brain  through  the  nerves ; but 
this  does  not  show  us  how  the  work  is  done.  We  find  that 
electricity  is  concerned  ; but  why  should  electricity  contract  a 
muscle  more  than  a wire  ? This  carries  us  to  the  end  of  our 
knowledge,  and  still  we  know  nothing  of  the  nature  of  that 
force  by  which  the  will  is  able  to  move  a muscle.  The  whole 
range  of  science  gives  not  the  slightest  clue  to  the  mystery. 
It  is,  in  fact,  as  profound  as  any  in  natural  or  revealed  relig- 
ion, and  until  we  can  solve  this  we  have  no  right  to  object  to 
any  religious  doctrine  on  the  ground  of  mystery. 

824.  — 2.  The  entire  connection  between  mind  and  matter 
teaches  the  same  lesson.  When  we  have  stated  the  facts  as 
to  their  mutual  influence,  we  have  nearly  reached  the  limit 
of  our  knowledge  of  the  subject.  There  is  no  physical  law 
or  mental  law  either  that  can  explain  their  action  and  reac- 
tion. All  attempts  to  do  this  amount  to  little  more  than  the 
vaguest  hypothesis.  Any  thinking  man  who  studies  the  phe- 
nomena will  be  impressed  by  the  mystery  that  hangs  over 
them,  and  if  he  be  a true  philosopher  will  be  slow  to  reject 
any  doctrine  of  religion  because  it  has  depths  in  it  which  he 
can  not  fathom. 


INDEX  AND  GLOSSARY.’ 


Th6  numbers  refer  to  the  page. 


A. 

Aboma'sum,  186, 187. 

Abdom'inal  muscles,  125. 

Abdom'inal  aorta,  211. 

Abdu'cent  nerves,  329. 

Acalefphi^  one  of  the  groups  of^  radiate 
animals. 

Access'ory  heart,  238. 

Aera'tion^  purifying  by  air. 

Afferent^  carrying  to. 

After  tastes,  409. 

Air,  amount  used  in  breathing,  253. 

“ “ of  in  lungs,  256. 

Albv/men,  a proximate  principle,  12. 
Albu'minose,  12. 

Algm^  sea  weeds. 

Ambulatory^  pertaining  to  a walk. 
Amor'phous^  without  shape. 
Amphiarthro'sis,  66. 

Anastomo'sis,  202. 

Anat'omy,  definition  of,  5. 

“ Comparative,  definition  of,  6. 

An'ehylosed^  grown  together. 
An/ractuos'ities^  depressions  on  the  brain. 
Angiol'ogy,  201. 

Angular  motion,  68. 

Animal  heat,  theory  of,  258. 

“ kingdom,  classification  of,  84,  85. 
Animal'cules^  minute  animals. 

An'nular^  like  a ring. 

“ ligaments,  132. 

Antisep'tiCy  preventive  of  decay, 

Aor'ta,  206. 

“ in  animals,  231. 

A'pex^  point  or  summit. 

Aponeuro'sis,  110. 

Appendages  of  cells,  18. 

A'qiieous  humor,  374. 

Aquiferous^  water  bearing. 

Arach'noid  membrane,  324. 

Ar'senic  in  the  body,  7. 

Arterialization— see  Aeration. 

Arteries,  204. 

“ and  veins,  comparative  capacity 
of,  223. 

Arthro'dia,  67. 

Articula'ta,  85. 

skeleton  of,  103. 

Artic'ulate^  to  make  a joint. 
ArtievZa'tions^  joints. 

" varieties  of,  66. 

“ anatomy  of,  67. 


Assimila'tion^  conversion  of  matter  into 
the  substance  of  the  body. 

Atmospheric  pressure  in  joints,  71. 
Audftion^  hearing. 

Au'ditory  nerves,  329. 

Au'ricles,  201, 

Automat'ic^  acting  apparently  without  the 
will. 

Ax'illary  artery,  206. 

Azot'ic,  containing  nitrogen. 

Az'oiised^  containing  nitrogen. 


Back  Board,  144. 

Basement  membrane,  17,  298. 

Beaded^  like  a string  of  beads. 

Belief,  effect  of  on  sensation,  368, 

Belly  of  muscles,  109. 

Benevolence,  Divine,  shown  by  anatomy, 
424. 

“ prospective  shown  in  organs, 

427. 

“ blended  with  pain,  428. 

Bicejjs  muscle,  119. 

Bicus'pid  teeth,  64. 

Bile,  16, 175. 

Bill  of  birds,  96, 189. 

Birds,  rate  of  flight,  154. 

Blaste'ma^  20. 

Blood,  15,  220. 

“ of  articulates,  241. 

**  vessels,  their  use,  222. 

“ “ “ large  amount,  223. 

Body,  its  size,  10. 

Bones,  chemical  composition  of,  31, 

“ mechanical  structure  of,  32. 

“ classes  of,  35. 

“ strength  of,  82. 

“ microscopic  structure  of,  83. 

“ intermaxillary,  89. 

“ jugal,  93. 

“ cor'acoid  in  birds,  96. 

“ sternal  “ “ 96. 

“ tarso-metatarsal,  in  birds,  97. 

**  sesamoid,  “ “ 97. 

“ development  of,  36. 

“ number  of,  37. 

“ uses  of,  74. 

“ distorted,  reason  of,  81. 

“ effect  of  wrong  position  on,  82. 

“ hollow  in  birds,  98. 

Brachial  artery,  206. 

Branchial  plexus,  334. 


434 


INDEX  AND  GLOSSARY 


Brain,  818,  842. 

“ of  mammals,  857. 

Breathing,  object  of,  253. 

Bronchi,  250. 

“ of  mammals,  270. 

Bronchi' inliamrnation  of  the  Bronchi. 
Brunner’s  glands,  163. 


C. 

CcRcal  cells^  closed  or  shut  sacs. 

Csecum,  161. 

Calca'reous^  hard  like  limestone. 
Cal'cijied,  made  hard  like  limestone. 
Cal'cium  in  the  body,  7. 

X,.  Calisthen'ics,  141. 

Callos'ities,  311. 

Calcutta,  blackhole  of,  266. 

Calorif'ic^  heat  producing. 

Canalic'uli  of  bones,  33. 

Ca'nine  teeth,  54. 

Cap'illaries,  214. 

Car'apace,  99. 

Carbon  in  the  body,  6, 

“ its  amount  given  oflT  from  the 
lungs,  255. 

Carbon'ic  acid  in  the  body,  10. 
Carniv'orou-%  flesh  eating. 

Carot'id  artery,  206. 

Carpus,  59,  78,  91. 

Cartilage,  in  vertebral,  42. 

Cartilag'inoua^  made  of  cartilage. 

Ca'sein,  12. 

Caudal  heart,  238. 

Cells,  18. 

“ vital  force  of,  21. 

**  chemical  changes  of,  21. 

vital  ization  of,  21. 

“ change  of  form,  21. 

“ periods  in  the  life  of,  21, 

Cellular^  having  cells. 

Cemen'tum,  51. 

Centrip'etal  and  centrif'ugal,  849. 
Ceph'alopod^  a molluscous  animal. 
Cerebellum,  319,  347. 

Cer'ebral  ganglia,  321,  348. 

“ hernispheres,  use  of,  341 

“ nerves,  358. 

Cer'ebro-spinal  center,  322. 

Cer'ebrum,  318. 

“ of  mammals,  357. 

Cer'vical  plexus^  334. 

Chem'ical  elements  of  the  body,  6. 
Chem'istry  and  vitality  combined  show  de- 
sign, 422. 

Chi'tine,  84,  314. 

Chit'inous,  containing  chitine. 

Chlorine  in  the  body,  7. 

Cho'roid  coat,  371. 

Chyla'queous  fluid,  241. 

Chyle,  15,  180. 

Choles'terlne,  11. 

Chvme,  175. 

minute  hairs. 

Cil'iary  processes,  871. 

Circle  of  Willis,  210. 

Circnla'tion  in  molluscs,  242. 

“ in  radiates,  243. 
Circiunduc'tion,  68. 

Clav'iclo,  67,  78,  96. 

C.Loa'cd^  a sac  appended  to  the  intestines. 
Coag'uLable^  capable  of  hardening. 


Coats  of  the  eye,  their  use,  378. 

Coch'lea,  891. 

Coe'eyx,  41. 

Coeliac  axis,  212. 

Colds  and  Coughs,  263.  

Colon,  162. 

Color  blindness,  383. 

Compound  eyes,  386. 

Cona'tuHy  attempt. 

Con'diments,  their  use  and  abuse,  184. 
Con'dyle^  elevation  or  eminence  on  a bone. 
Con'voluted^  rolled  together  like  a tube. 
Coordina'iion^  working  or  designing  to- 
gether. 

Copper  in  the  body,  7. 

Cor'acoid  bone,  96. 

Coria'ceous^  like  leather. 

Co'rium,  298,306. 

Cor'nea,  370. 

Cor'neous^  like  horn. 


Cor'pora  stria'ta,  32^ 

Cor'pudcltfi^  little  bodies  or  cells. 

“ of  blood,  220,  228,  254. 
Corpulence,  its  effect  on  capacity  of  lungs 
254. 


Corpus  callosum,  319. 

Cra'nium^  skull. 

Cra'nial  nerves,  325-331. 

Cre'ation,  9. 

Cric'oid  cartilage,  260. 

Cruata'ceana^  animals  like  the  crab  and 
lobster. 

Ctenoi'dians,  314. 

Cubical  size  of  the  body,  10. 

Cune'iform  cartilage,  260. 

Cuta'neous^  relating  to  the  skin, 

Cu'ticle,  296. 

Cycloi'dians,  314. 

Cyiogerdesia,  cell  production. 


D. 

Daily  water  bath,  310. 

Daltonism,  383. 

Death  universal,  429. 

Decuaaa'tion^  crossing  like  an  X. 
Degluti'tion,  172. 

Deity,  argument  for,  from  anatomy,  420. 
Den'tine,  51. 

Denti'tion^  appearance  of  teeth. 

Den'izen^  an  inhabitant. 

Dermatol' ogy^  science  of  the  skin. 

Dermis^  skin. 

Development  hypothesis,  argument  against, 
431. 

Development  hypothesis,  disproved  by  an- 
nular ligaments,  431. 

Diarthro'sis,  67. 

Di'aphragm,  124, 150. 

Dias'tole,  226. 

Diet  best  adapted  for  man,  177. 

Digas'tric  muscle,  116. 

Diges'tion,  its  theory,  174, 175. 

Dip'loe  of  cranium,  76. 

Diaasaimila'tion^  process  of  waste. 

Disease  not  to  be  avoided,  428. 

“ of  circulatory  organs,  228. 

Dorsal  vessel,  239. 

Duode'nal  glands,  163. 

Duode'num,  160. 

Duplica'tive  folding  or  doubling. 

Dura  mater,  823. 


INDEX  AND  GLOSSARY 


435 


K 

Ear,  389. 

“ a proof  of  design,  420. 

“ functions  of  all  its  parts,  394,  397. 

“ of  animals,  297,  399. 

Eating,  hygienic  inferences  from,  183,  184. 
Echin'oderras^  radiate  animals. 

Ef'ferent,  carrying  away  from. 

Electrical  organs  of  fishes,  360. 

Elemen'tary  tissue,  14. 

Emacia'tion^  wasting  away. 

Enam'el,  51. 

Enarthro'sis,  67. 

En'dosmose,  17. 

Epider'mis,  296. 

“ use  of,  305,  306. 

Epider'mic  scales,  311. 

Epiglot'tis,  261. 

EpUhe'lial,  relating  to  the  epithelium. 
Epithe'lium^  outer  surface  of  mucous  and 
other  membrane. 

Esoph'agus,  157. 

“ of  horse,  186. 

Eusta'chian  tube,  891. 

Evil  incidental  not  intentional,  425. 

« “ to  every  function,  429. 

Excrementi'tious^  waste  or  superfluous. 
Ex'osmose,  17. 

Extremities,  anterior,  of  quadrupeds,  92. 
Exuda'tions,  15. 

Exuvia'tion^  casting  off. 

“ of  serpents,  313. 

Eye,  anatomy  of,  369. 

“ a proof  of  design,  420. 

Eyebrows,  876,  380. 

Eyelids,  376,  380. 

Eyes  of  mammals,  383. 

“ “ birds,  384. 

“ “ reptiles,  385. 

“ » fishes,  386. 

“ “ insects,  386. 

“ “ mollusca,  888. 

« “ radiata,  388. 

F. 

Facfet^  a little  surface  or  face. 

Face,  47. 

Fa'cial  nerves,  329,  851. 

Fats  in  the  body,  11. 

Feathers,  312. 

Fel'on,  35. 

Fem'oral  artery,  212, 

Fe'mur,  63,  79,  97,  100. 

Fever  sore,  35. 

Fiber,  simple,  17. 

“ muscular,  107. 

Fi'bril,  “ 107. 

“ in  contraction,  137. 

Fibrin,  12. 

Fib'ula,  63. 

Flu'orine  in  the  body,  7. 

FoFlicles,  289. 

“ of  Lieberkuhn,  163. 

Food,  for  what  purposes  required,  176. 
Foram'ina  of  bones,  35. 

Forces  of  blood  circulation,  223,  226. 

Fore  arm,  58,  78. 

Fright,  effect  of  on  hair,  815. 

Frontal  bone,  43. 

Functions,  the  mode  for  their  performance, 
425. 

Fu'siform^  spindle  shaped. 


G. 

Gall-Bladder,  165. 

Gang'lia^  small  knots  or  masses  of  nervous 
matter. 

Ganglia,  uses  of,  350. 

Ganoid'ians,  314. 

Gastric  Juice,  15,  173. 

“ follicles.  159. 

“ artery,  212. 

Ge'nus^  a group  of  species. 

Gills  of  Fishes,  274. 

Gin'glymus  joint,  67. 

Giz'zard^  second  stomach  of  fowls. 

Glands,  their  anatomy,  289. 

“ ductless,  292. 

“ of  the  skin  in  mammals,  312. 

Gliding  motion,  68. 

Glob'ule^  spherical  particle  of  matter. 
Glob'ulin,  12. 

Glosso-pharyngeal  nerves,  830,  351. 

Glu'ten,  12. 

Glu'teus  muscle,  128. 

Gompho'sis,  66. 

Granules  of  cells,  18. 

“ “ bone,  34. 

Gymna'sia,  their  use,  141,  144. 


H. 

Habit,  effect  of  on  sensations,  868,  402. 

Hair,  number  and  distribution  of,  303. 

“ chemical  composition  of,  303. 

“ constitution,  color,  and  properties  of, 
304.  ^ • 

**  rate  of  its  growth,  305. 

variety  of,  in  mammals,  811. 

ITamsterj  a rodent  animal. 

Happiness  the  object  of  all  organs,  424. 

Harde'rian  gland,  283. 

Harmo'nia,  66. 

Haver'sian  canals,  33. 

Head  of  birds,  93. 

Heart  of  man,  201. 

“ “ mammals,  230. 

“ “ birds,  232. 

“ “ reptiles,  234. 

“ “ crocodile,  236. 

“ “ fishes,  237. 

“ “ articulates,  239. 

“ “ Crustacea,  241. 

Heat  producing  organs,  256. 

Hem'atin,  13. 

Hepat'ic^  pertaining  to  the  liver. 

“ artery,  212. 

Herhiv'orous,  vegetable  eaters. 

Hexag'onal^  with  six  sides. 

Hippu'ric  acid,  9. 

Hiss  of  serpents,  272. 

HUtogeneVic^  tissue  making. 

Histol'ogy^  14. 

Homoge'neous^  of  the  same  character 
throughout. 

Honey  comb,  187. 

Horn  of  rhinoceros,  311. 

Hu'merus,  57,  91,  97, 100. 

Humors  of  the  eye,  374,  878. 

Hy'drogen  in  the  body,  6, 

Hygrol'ogy,  14. 

Hyoid  bone,  65. 


436 


INDEX  AND  GLOSSARY 


I. 

Ichorol'ogy,  definition  of,  282 
Il'iac  arteries,  212. 

Il'iiim,  61. 

Imbibi'tion,  17. 

Im'bricated^  overlapping  like  shingles  on 
a roof. 

Imine'diate  principles,  7. 

Impurities  exhaled  from  lungs,  255. 

Inci'sor  teeth.  54. 

Indian  club,  145. 

Infaso'Ha^  microscopic  animals. 

Inglu'vies,  188. 

Iiinomina'tum,  61. 

Jnoscula'tion — see  anastomosis. 
Inspirations  compared  with  pulsations,  255. 
Interartic'ular  cartilage,  71. 

Intercos'tal  muscles,  125. 

Intermax'illary  bones,  89. 
lateross'eou.^^  between  the  bones. 
Intes'tinal  fluid,  16. 

“ glands,  163. 

Intes'tine,  length  of,  155,  189, 192. 
Iriver'tebrate^  without  internal  skeleton. 
Iris,  371. 

Iron  in  the  body,  7. 

Irritability  of  muscular  fiber,  134. 

Is'chium,  61. 

J. 

Jeju'num,  161. 

Joints,  design  shown  in  them,  421. 

“ motions  of,  68. 

Jugal  bone,  93. 

£. 

Kidneys,  171. 

L. 

Lab'yrinth,  391. 

Lach'rymal  gland,  375. 

“ bones,  49. 

Lac'teals,  169,  180,  282. 

Lacn'iioBi  spaces. 

“ of  bone,  33. 

Laeu'nar^  filled  with  lacunae. 

Lamell'ce^  thin  lay^ers  or  plates. 
Larijn'geal^  relating  to  the  Larynx. 

“ pouches,  279. 

Lar'ynx,  248,  259. 

“ of  birds,  279. 

“ “ reptiles,  280. 

“ its  similarity  to  a reed  instru- 

ment, 264. 

Lead  in  the  body,  7. 

L'Uis  of  the  eye,  374. 

l.lfo,  characteristic  of  organic  substances,  5. 
Lig^ameuts,  69. 

annular,  show  design,  423. 

“ used  as  braces,  74. 

Lime,  carbonate  and  |)hosphate  of,  11. 
Lin'gual  nerves,  831,  851. 

Liver,  165. 

“ of  mammals,  189. 

“ “ fishes,  193. 

Lob'ulcs  of  lung,  247. 

Lower  Jaw,  50,  89. 

Lumbar  arteries,  212. 


Lumbar  plexus,  834. 

Lunglet^  lobule  of  lung. 

Lungs,  their  liability  to  disease,  265. 

“ “ action  essential  for  health,  266. 

**  pure  air  essential  to,  266. 

“ capacity  of,  as  affected  by  postiiro, 
267. 

“ capacity  of  may  be  increased,  267. 

“ of  mammals,  270. 

“ “ birds,  270. 

“ “ reptiles,  272. 

Lymph,  15. 

Lymphat'ics,  182,  284. 

“ their  function,  287. 

“ material  absorbed  by,  287. 

Lymphat'ic  hearts,  236. 

“ glands,  285. 

M. 

Magne'sium  in  the  body,  7. 

Malar  bones,  48. 

Malle'olus,  64. 

Man  not  without  hope,  429. 

Manganese'  in  the  body,  7. 

Man'dible,  50,  89. 

Mantle  of  Molluscs,  314. 

Mauy-plies,  187. 

Marmot^  a rodent  or  gnawing  animaL 

Mass'eter  muscle,  116. 

Mastication,  172. 

Me'dia^  or  humors. 

Medull'a  oblonga'ta,  322,  847, 

Medidnce,^  radiate  animals. 

Meibo'mian  glands,  377. 

Membra'na  tym'pjini,  390. 

Membrane,  simple,  17. 

Mesenter'ic  artery,  212. 

“ glands,  169. 

Mes'entery,  168. 

Metamor' phoHia^  change. 

Metacar'pus,  60,  79,  91. 

Metatar'sus,  65. 

“ of  birds,  97. 

Milk,  16. 

Mimo'sa^  plant  of  the  order  leguminosje. 

Moisture,  its  effect  upon  lymphatics,  289. 

Molar  teeth,  54. 

Mollusca,  85. 

“ skeleton  of,  104. 

Motor ^ exciting  motion. 

“ nerves,  336. 

“ oculi,  326,  351. 

Mouth,  155. 

Movements  of  radiata,  153. 

Mu'cus,  15. 

Muscles,  number  of  in  man.  111. 

“ suspensory,  152. 

“ of  birds,  feathers,  152. 

“ design  shown  in  them,  421, 

“ looped,  show  design,  422. 

“ need  use,  139. 

“ “ gradual  rest,  140. 

“ require  regular  exercise,  140. 

“ time  they  may  be  employed,  154 

“ forms  of,  110. 

“ of  the  fore  arm,  120. 

“ “ birds,  151. 

“ “ fishes,  152. 

“ “ articulates  and  molluscs, 

153. 

Muscular  development,  141. 


INDEX  AND  GLOSSABY 


437 


Muscular  strength,  examples  of,  137, 154. 

“ contraction,  cause  of,  135. 

“ movement,  disadvantage  of  it,  136. 

“ contraction,  its  rapidity,  138. 

“ “ “ duration,  138, 

“ “ “ precision,  139. 

Mus'culin,  12. 

Myol'ogy,  definition  of,  107. 

Myotil'ity,  26,  134. 

Mystery  as  great  in  physiology  as  in  relig- 
ion, 432. 

Mystery  in  muscular  movement,  432. 

“ in  connection  of  mind  and  matter, 
432. 

N. 

Nails,  277. 

Nasal  bones,  48. 

“ duct,  375. 

Nasmyth’s  membrane,  53. 

Neck,  its  length  dependent  on,  87. 

I “ how  to  be  dressed,  269. 

Nerve  tubes  and  fibers,  317. 

“ vesicles  or  cells,  318. 

Nerves  over  sensitive,  428. 

Nervous  power  shows  design,  423. 

“ system,  its  hygiene,  352, 
Neurol'ogy,  definition  of,  316, 

Nictitating  membrane,  383. 

Ni'trogen,  6. 

Nitrog' enouiy  containing  nitrogen. 

Norraaly  according  to  the  standard. 

Nose,  412. 

Nostrils,  413. 

their  use  in  the  voice,  265. 
Nu'clear,  pertaining  to  a nucleus. 
Nu'cleatmy  18. 

Nucle'olus,  18. 

Nu'cleus,  18. 

O. 

Oil,  16. 

“ glands,  299. 

“ “ use  of,  307. 

O'lein,  11. 

Olfac'tory  nerves,  825,  850. 

Oma'sum,  187. 

Ornen'tum,  168. 

Optic  nerves,  326,  351. 

Orbicula'ris  pal'pebrae,  114. 

“ oris,  115. 

Organ,  definition  of,  29. 

Organs  adapted  to  circumstances,  426. 
Ornithoryn'chuSy  an  animal  of  the  class 
mammalia. 

Os'cUlaioryy  vibrating. 

Oss'icleHy  little  bones. 

Os  quadra'tum,  397. 

Os'teiu,  12. 

Osteol'ogy,  definition  of,  31. 

OVolithSy  bony  particles  of  the  ear. 
Ovalbu'men,  12. 

Ox'ygen  in  the  body,  6. 

P. 

Pacin'ian  coipuscles,  336. 

Pal'ate  bones,  49. 

Palmar  arch,  209. 

Pan'creas,  166. 

Pancreat'ic  fluid,  16. 

Papil'lae,  295,  400,  408. 

Par^asite  of  skin,  299. 


Pari'etal  bone,  44. 

Patell'a,  63. 

Paunch,  187. 

Pecten  marsu'pium,  384 
Pedun'cley  a stalk  or  stem. 

Pedun'culatedy  having  a stalk  or  peduncle. 
Pelvis,  bones  of,  61. 

Pen'niformy  feather-shaped, 

Pep'sin,  15, 160. 

Pericardium,  204 
Per'ilymph,  391. 

Peri  os' teum,  34. 

PeristaVtiCy  moving  like  a worm. 
Peritone'um,  168. 

Perspira'tion,  301. 

Peyer’s  patches,  163. 

Phalanges,  60,  65,  79,  91,  97. 

Pharyn'gealy  belonging  to  the  pharynx. 
Pha'rynx,  156. 

Phos'phorus  in  the  body,  7. 

Physiology,  definition  of,  6. 

Pia  ma'ter,  324 
Pig'ment  cells,  296. 

Pigmen'tary  spots,  385. 

Pigmen'tum  ni'grum,  372. 

Pinna,  389. 

Pitu'itary  membrane^  the  lining  mem- 
brane of  the  nose. 

Placoid'ians,  314. 

Plan,  unity  of,  in  animal  system,  424. 
Plasma^  watery  portion  of  the  blood. 
Plas'tron,  99. 

Pleasure  superadded  to  functions  when  not 
necessary,  425. 

Pleura,  248. 

Pleurisy,  248. 

Plexus,  332. 

Pneumogas'tric  nerves,  330,  351. 
Pneumonol'ogy,  definition  ot^  244. 

Poison  introduced  by  lymphatics,  288, 
Polyhe'draly  with  many  ends. 

PolypHy  radiate  animals. 

Poplit'eal  artery,  213. 

Pores  of  bones,  34. 

Portal  system,  218,  236. 

Potass'ium  in  the  body,  7. 

Power  reserved  for  exigencies,  426. 

“ vicarious  in  organs,  426. 

“ recuperative  in  the  system,  427. 

Prehen/ silCy  adapted  for  seizing. 
Prehen'sioiiy  the  act  of  grasping. 

Primary  tissue,  14,  22. 

Principles,  immediate,  grouped,  8,  9. 
Prismoidy  like  a prism. 

PHs'tiney  primary. 

ProcesSy  an  elevation  on  a bone. 

Processes  of  bones,  35. 

Pro'tein,  13. 

Psoas  muscle,  126. 

Pty'alin,  172. 

Pu'bis,  61. 

Pulsations  of  heart,  227. 

Pylor'ic  appendages,  194. 

Pylo'ruSy  tne  lower  orifice  of  the  stomach, 

Q. 

Quadran'gulaVy  with  4 angles. 
Quadrilai'eraly  “ “ sides. 

R. 

Ra'dial  artery,  208. 

Badia'ta,  85. 


438 


GLOSSARY 


INDEX  AND 


Radiata^  skeleton  of,  106. 

Radicals,  organic,  8. 

Ra'dius,  59. 

JRam'ify^  to  give  off  branches. 

Rectum,  162. 

Red  or  Rennet,  ISS. 

Reflex  actions  in  articulates,  363. 

Religious  applications  of  anatomy,  420. 
Respira'tion,  process  of,  252. 

Respi'ratorv  organs  of  mammals,  270. 

“ “ birds,  270. 

“ reptiles,  272. 

« “ fishes,  275. 

“ “ “ articulates,  276. 

“ “ “ molluscs,  278. 

“ “ “ radiates,  279. 

Retic'ulum,  186. 

Ret'ina,  372. 

Retractile^  capable  of  being  drawn  back. 
Ribs,  55,  96. 

Rickets,  cause  of,  82. 

Ro'dent^  gnawing. 

Rota'tion,  68. 

Ru'minant,%  animals  that  ehew  the  cud 
like  the  cow. 


s. 

Sa&ciform^  like  a sac. 

Sa'cral  plexus,  334. 
iSa'crum,  41. 

Sali'va,  16, 172. 

Sal'ivary  glands,  155. 
fealt  in  the  human  body,  11. 

Sapona'ceous^  soapy. 

Sarcolem'ma,  108. 

Scales  of  serpents,  313. 

“ “ fishes,  314. 

Scap'ula,  57. 

Scepter,  Indian,  145. 

Schindyle'sis,  66. 

Science,  its  highest  use,  420. 

Seba'ceous  glands,  299. 

Sclerot'ica,  369. 

Scle'roii-%  hard  like  bone. 

Secrc'tion,  vicarious,  292. 

“ after  death,  291. 

“ function  of,  291. 

“ effect  of  emotions  upon,  291. 
Seo'ment.%  divisions. 

Sernicir'cular  canals,  391. 

Sensa'tions,  effect  of  habit  upon,  868,  402. 
Senses  often  a source  of  misery,  418. 

“ dependent  on  mind,  367. 

“ effect  of  excessive  use  of,  867. 

“ development  in  lower  animals,  867. 
Sensual  happiness  not  perfect,  419. 
Seralbu'rnen,  12, 

Serra'tl  muscles,  125. 

Se'rum,  15. 

Scs'amoid  bones,  65,  97. 

Sighted,  long  and  short,  381. 

Sil'icon  in  the  body,  7. 

Si'nuses,  217. 

Skeleton,  design  showed  In,  421. 

“ human,  weight  of,  82. 

Skin,  295. 

“ uses  of,  305. 

“ its  hyglen'ic  value,  308. 

“ attention  nece.ssary  for,  809,  810. 

“ of  mammals,  810. 

“ “ birds,  812. 


Skin  of  amphil/ki,  813. 

“ “ ra'<liatcs,  815. 

Sleep,  342,  847. 

Smell  under  control  of  the  will,  414i. 

“ sense  of,  in  animals,  414,  416. 

So'dium  in  the  body,  7. 

Solar  plexus,  340. 

Solitary  glands,  163. 

Sound,  organs  essential  for,  264. 

Sounds  of  heart,  227. 

**  “ insects,  280. 

“ “ mollusca,  281. 

Special  sense,  nerves  of,  868. 

Sphe'noid  bone,  45. 

Sphinc'ter,  111. 

Spinal  cord,  322,  3.32,  343. 

“ column,  42,  78,  85. 

“ nerves,  332, 352,  353. 

“ accessory  nerve,  330,  SSL 
Spi'racles  of  insects,  276. 

Splanchnol'ogy,  155. 

Spleen,  293. 

Sple'nic  artery,  212. 

StelL'ate^  star-shaped. 

Siem'mata^  387. 

Sternum,  55,  96,  101. 

Sterno-cleido  mastoid  muscle,  116. 
Stim'ulants,  their  value  and  injury,  185. 
Stomach,  158. 

“ of  ruminants,  187. 

“ “ birds,  190. 

Styloid  bones,  89. 

Subcla'vian  artery,  206. 

Sugar  in  the  body,  11. 

Sulphur  “ “ 7. 

Superior  Max'illary,  50. 

Suppura'tion^  forming  of  pus. 

Suspen'sory  muscle,  152. 

Siitu'ra,  66. 

Su'tures,  46. 

Sweat,  17. 

“ glands,  299. 

Sympathet'ic  system,  337, 348,  853. 

“ ganglia,  339. 

Sympathy  between  heart  and  lungs,  245. 
Sym'physes,  67. 

Synarthro'sis,  66. 

Syn'c/ironou-%  at  the  same  time. 
Syndesmol'ogy,  definition  of,  66. 

Syno'vial  membrane,  73. 

Systems  of  organization  mutually  depend- 
ent, 424. 

Sys'tole,  226. 

T. 

Tac'tile,  susceptible  of  touch. 

Tailor’s  muscle,  129. 

Tape'tum,  383. 

Tarso-metatar'sus,  97. 

Tarsus,  64,  81. 

Taste,  nerves  of,  407. 

“ effect  of  education  upon,  403. 

“ its  connection  with  smell,  409. 

“ a guide  for  the  appetite,  418. 

Tears,  16,  380. 

Teeth,  human,  51. 

“ esophage'al,  192. 

“ of  reptiles,  191. 

“ of  flslies,  102. 

“ development  of,  53. 

“ names  of,  54,  90. 

“ fracture  of,  6^ 


INDEX  AND  aLOSSART 


439 


Teeth,  care  needed  for,  82. 

“ generally  decay  early  in  life,  83. 
Teg'ument  of  articulata,  314. 
TegumenVary,  relating  to  the  skin. 
T^gument'ary  muscle,  150. 

1 einperature  of  human  body,  257. 
Teui'poral  bone,  43. 

‘‘  muscle,  116. 

Tendons  of  fingers  and  toes,  120. 

“ ossification  of,  in  birds,  151. 

Tensor  vag'inje  fem'oris,  129. 

Tento'rium,  358. 

Thal'ami  op'tici,  322. 

Thoracic^  pertaining  to  the  chest. 
Thorac'ic  duct,  170. 

“ aorta,  211. 

Thy'roid  cartilage,  260. 

Tib'ia,  63. 

Tib'ial  artery,  213. 

Time  during  which  .muscles  can  be  used, 
154. 

Tissue,  simple  fibrous,  22. 

“ white  fibrous,  22. 

“ yellow  “ 22. 

“ areolar,  23. 

“ fibro-cellular,  23. 

“ cellular,  24. 

“ sclerous,  24. 

“ tubular,  25. 

“ muscular,  26. 

“ nervous,  28. 

Tobacco,  its  effect  on  the  brain,  355. 
Tongue,  human,  406, 

“ of  reptiles,  191. 

“ use  oi;  in  speech,  265. 

Tonic'ity,  muscular,  134. 

Tonsils,  155. 

Tortoise  shell,  99. 

Touch,  instruments  of,  400. 

**  of  lower  animals,  403,  405. 

Tra'chea,  248. 

“ of  mammals,  270. 

“ “ insects,  276. 

Transverse^  crosswise. 

Transuda'tions,  15. 

Triangle  for  exercise,  145. 

Triceps  muscle,  119. 

Trifa'cial  nerves,  326,  351. 

Trill  of  birds,  279. 

Triquet'ra  ossa,  47. 

Trochan'ter  process  upon  the  upper  part 
of  the  femur. 

Troch'lear  nerves,  326. 

Tuberc'ula  quadrigem'ina,  322. 

Tur'binal  bone,  49. 

Tym'panic  bones,  88. 

Tym'panum,  390. 


V. 

TTlcera'tio%  ulcer-forming. 

Ulna,  58. 

Ulnar  artery,  208. 

Unicel'lular  animals,  199. 

Uniformity  of  animal  heat,  258. 

Unity,  Divine,  proofs  of  from  anatomy,  430. 
“ “ proved  by  the  conspiration 

of  all  the  parts,  430. 

Unity  proved  by  mutual  relation,  430. 
Urine,  16. 


V. 

Yalves  of  the  heart,  203. 

Veins,  217. 

“ valves  of,  their  discoverer,  219. 
Ventral  trunk,  241. 

Ven'tricles,  202. 

“ of  brain,  324. 

Ventu'ri,  principle  of,  181. 

Ver'tebra,  cervical,  40,  85,  93. 

“ dorsal,  41,  85,  93. 

“ lumbar,  41,  85. 

“ sacral,  85. 

“ caudal,  85,  93. 

Ver'tebral  artery,  209. 

Vertebra'ta,  85. 

Vessels  protected,  423. 

Ves'tibule,  391. 

susceptible  of  vibration, 
hair-like  appendages. 

Viscera.,  contents  of  an  animal  cavity. 
Viscidy  thick  like  syrup. 

Vision,  limits  of,  382. 

Vitaliza'tion.,  the  act  of  giving  life. 
Vitreous  humor,  875. 

Vocal  cord,  262. 

Voice,  organs  of,  259. 

“ its  strength  dependent  on,  269. 
Voluntary  motions,  on  what  dependent^ 
340. 

Vo'mer,  51. 

W. 

Waste  the  cause  of  muscular  contraction, 
135. 

Water  in  the  body,  10. 

“ amount  consumed  by  an  adult,  11. 

“ “ discharged  by  the  skin,  302L 

Wax,  16. 

Wonder  nets,  231,  234. 

Wounds  of  arteries,  229. 

World  fallen,  proof  of,  from  anatomy,  4281 


INDEX  OF  CUTS 


FIG.  PAGE 

1 Blood  Crystals 9 

2 “ “ 10 

8 “ “ 13 

4 Milk 16 

5 Simple  Fiber 17 

6 Cells 18 

7 “ 18 

8 Caudate  Cells 19 

9 Stellate  “ 19 

10  Development  of  Cells 20 

11  “ “ “ 20 

12  “ « “ 21 

13  White  Fibrous  Tissue 22 

14  Yellow  “■  “ 22 

15  Areolar  Tissue 23 

16  Cells  of  Areolar  Tissue 23 

IT  Adipose  Tissue 24 

18  Cartilaginous  Tissue 24 

19  Osseous  “ 25 

20  Lacuna  of  Bone 25 

21  Lymphatic  Vessel 26 

22  Muscular  Tissue 26 

23  Diagram  of  Muscular  Fibril..  26 

24  Muscular  Tissue 27 

25  “ « 27 

26  “ “ 27 

27  Tubular  Nerve  Tissue 28 

28  Vesicular  “ 28 

29  “ “ “ 29 

30  Fibula  after  Immersion  in  Mu- 

riatic Acid 32 

81  Canaliculi  of  Bone 33 

82  Lacunje  “ “ 34 

83  Ultimate  Granules  of  Bone..  84 

84  Periosteum 85 

85  Development  of  Cartilage...  37 

86  Knee  Joint 88 

87  Lateral  View  of  Spinal  Col..  38 

88  View  of  Human  Skeleton 89 

89  Atlas 40 

40  Axis 40 

41  A Dorsal  Verteiira 41 

42  Sacrum 41 


PAGE 


Coccyx 41 

A Dissected  Skull 43 

Frontal  Bone 43 

Temporal  “ - . • 44 

Parietal  “ 44 

Occipital  “ 45 

Sphenoid  “ 45 

Ethmoid  “ 46 

Vault  of  the  Cranium 46 

Front  View  op  the  Skull....  47 

Nasal  Bones 48 

Malar  Bone 48 

Lachrymal  Bone 49 

Palate  “ 49 

Turbinal  “ 49 

Maxillary  “ 50 

Mandible 50 

Vomer 51 

Section  of  Human  Incisor  ....  52 
“ “ “ Bicuspid....  52 

“ “ “ Incisor  ....  52 

“ “ “ Molar 52 

Enamel  of  Tooth 53 

Permanent  Teeth 54 

Hyoid  Bone 55 

Sternum 55 

Upper  Bib 55 

Eibs 56 

Bonks  of  the  Chest 56 

Clavicle 57 

Scapula 58 

Humerus 58 

Fore- Arm 59 

Carpal  Bones 60 

Bones  of  the  Hand 60 

Pelvis 61 

Innominatum 62 

Femur 62 

Patella 63 

Tibia  and  Fibula 64 

Bones  of  the  Foot 64 

Development  of  Cartilage....  69 
Ligaments  of  the  Pelvis TO 


FIG. 

43 

44 

45 

46 

47 

48 

49 

50 

51 

52 

53 

54 

55 

56 

57 

58 

59 

60 

61 

62 

63 

64 

65 

66 

67 

68 

69 

70 

71 

72 

73 

74 

75 

76 

77 

78 

79 

80 

81 

82 

83 

84 


INDEX  OF  CUTS.  44^ 


fig.  page 


86  Ligaments  OP  THE  Shoulder.  .. . 70 

8T  “ “ “ Hip 71 

88  “ “ “ Knee 71 

89  “ “ “ Lower  Jaw.  72 

90  “ “ “ Vertebra 

AND  Ribs 72 

91  Ligaments  of  the  Elbow 72 

92  “ “ “ Ankle 73 

93  “ “ “ Foot 73 

94  “ “ “ Ankle 74 

95  Skeleton  op  Camel 86 

96  “ “ Bat 86 

97  “ “ Cameleopard  ....  87 

98  “ “ Mole 88 

99  Head  of  Horse 89 

100  Teeth  of  Lion 90 

101  Teeth  of  an  Herbivorous  Ani- 

mal  91 

102  Teeth  of  an  Insectivor.  Animal  91 

103  Anterior  Extremities  op  Dif- 

ferent Animals 92 

104  Hind  Foot  of  Horse 92 

105  Foot  op  Stag 92 

106  Skeleton  of  Swan 94 

107  “ “ Gceland 95 

108  Head  of  Eagle 95 

109  Bones  of  Sternum  & Shoulder.  96 

110  Skeleton  of  Tortoise 99 

111  “ “ Frog 100 

112  “ “ Perch 101 

113  Section  of  the  Scale  of  Lepi- 

dosteus 101 

114  Head  of  the  Pike 102 

115  “ “ « Shark 102 

116  Microscopic  Structure  op 

Tooth  of  Eagle  Kay 103 

117  Microscopic  Structure  of  Spine 

of  Hedgehog 104 

118  Microscopic  Yiew  of  Shell  op 

Pinna 105 

119  Microsc.  View  of  Shell  of  Mya  105 

120  Development  op  Muscul.  Fiber  107 

121  Fragments  “ “ “ 108 

122  Muscular  Fibril 108 

123  Section  of  Fibril 109 

124  Myolemma 109 

125  Cells  of  Muscular  Fiber 109 

126  Radiate  Muscle 110 

127  Fusiform  “ HO 

128  Doubly  Penniform  Muscle  ....  Ill 

129  Muscular  System 112 

130  “ “ 113 

131  Transverse  Section  of  Neck.  . . 114 

132  Muscles  of  Face  and  Neck 115 

133  « “ “ “ “ Side 

View 117 


fig.  ‘ PAGE 

134  Muscles  of  Back 118 

135  « “ Arm 119 

136  “ , “ Hand  & Fore-Arm.  120 

137  “ “ Palm  of  Hand 121 

138  “ “ Fore-Arm  (deep 

Layer) 121 

139  Muscles  of  Back 123 

140  Diaphragm 125 

141  Muscles  of  Trunk  (Side  View).  12G 

142  “ “ Abdomen 127 

143  “ “ Thigh 128 

144  “ “ “ (Back  View)..  130 

145  “ “ Front  OF  Leg 130 

146  “ “ Back  OF  Leg 131 

147  “ “ Foot. 132 

148  “ “ Back  of  Fore- Arm.  133 

149  “ “ Front  of  Leg 133 

150  Diagram  of  Fibrill^ 134 

151  “ “ Disadvantage  op 

Muscular  Action 136 

152  Muscular  Fiber  Contracting.  . 137 

153  Back  Board 144 

154  “ “ IN  Use 145 

155  Indian  Club 145 

156  Uses  of  Indian  Club 146 

157  Triangle 145 

158  Use  of  Triangle 145 

159  Apparatus  of  a Gymnasium.  . . . 147 

160  “ “ “ ....  148 

161  “ “ “ •....  149 

162  Fibrils  of  Pig 151 

163  “ “ Meat  Fly 153 

164  Insect  Fasciculi 153 

165  Salivary  Glands 156 

166  Follicles  from  Tonsils 156 

167  Section  of  Mouth  and  Pharynx  157 

168  Esophageal  Glands 158 

169  Human  Stomach 158 

170  Coats  of  “ 159 

171  Diagr.  of  Stomach  a Intestines  160 

172  Gastric  Glands 160 

173  Cjecum  and  Appendix 161 

174« Human  Digestive  Apparatus.  . 163 

175  Peyer’s  Patches 164 

176  Brunner’s  Gland 164 

177  Villi  of  Jejunum.. 164 

178  Human  Liver 166 

179  Lobule  of  Liver 166 

180  Gall  Bladder 167 

181  Pancreas  and  Spleen 167 

182  Peritoneum 168 

183  Chyliferous  Vessels 169 

184  Thoracic  Duct 170 

185  Kidney 171 

186  Diagram  op  Urinary  Appara- 

tus  171 


442 


INDEX  OF  CUTS. 


fig.  page 

187  Diagkam  of  Position  of  Thora- 
cic Duct  and  Jugular  Vein..  181 
183  Principle  of  Venturi 182 

189  Digestive  Apparatus  of  Ape...  186 

190  Stomach  of  Sheep 187 

191  Interior  of  “ 187 

192  Stomach  OF  Ox 188 

193  Head  of  Woodpecker 189 

194  Digestive  Apparatus  of  Fowl  190 

195  Head  of  Rattlesnake 191 

196  Anatomy  of  Snake 193 

197  Digestive  Apparatus  OF  Beetle  194 
193  Viscera  of  Aplysia  (Mollusc).  195 

199  “ “ Star  Fish 195 

200  Fresh  Water  Polyp 197 

201  Digestive  Apparatus  of  uni- 

cellular Animals 198 

202  Human  Heart 201 

203  Fibers  of  the  Heart 202 

204  Heart  and  Lungs 202 

205  Diagram  of  Heart 203 

206  Valves  of  Heart 204 

207  “ “ Aorta 204 

203  Arterial  System 205 

209  Middle  Coat  of  Arteries 206 

210  Heart  and  Arteries  in  Situ....  207 

211  Arteries  of  Neck  & Shoulder  . 208 

212  “ “ Arm  AND  Hand....  209 

213  Circle  of  Willis 2l0 

214  Abdominal  Aorta 211 

215  Femoral  Artery 212 

216  Arteries  of  Backside  of  Leg...  213 

217  Capillaries 214 

218  Veins  of  Face  and  Neck 215 

219  “ “ Trunk  and  Neck 216 

220  Sinuses  of  Brain 217 

221  Valves  of  Veins 218 

222  Veins  of  Arm 219 

223  “ “ Leg 220 

224  Blood  Crystals 221 

225  Bed  Blood  Corpuscles 221 

226  Diagram  of  Heart’s  Contract..  227 

227  Circulation  in  Mammals 230 

228  t)  I AG  RAM  of  Varieties  of  Aorta 

IN  Mammals 231 

229  Blood  Corpuscles  of  Ox 231 

230  Blood  Crystals  of  Guinea  Pig.  232 

231  Arteries  of  the  Grebe 233 

232  Pigeon  Blood  Corpuscles 234 

233  Diaor.  of  Circulat.  of  Beptiles  234 

234  Blood  Corpuscles  of  Frog 234 

235  Circulat.  Apparatus  of  Lizard  235 

2;’, 6 Heart  OF  Crocodile 236 

237  “ “ Turtle 236 

23®  F)ia<;kam  OF  Circulat.  OF  Fishes  237 
239  Circulating  Vessels  IN  THE  Fish  238 


fig.  page 

240  Blood  Corpuscles  or  Eel 239 

241  Plan  of  Circulation  in  Fishes.  239 

242  Circulatory  Apparatus  of  the 

Lobster 240 

243  Circulat.  Apparatus  of  Insects  240 

244  Blood  Corpuscles  of  Crab 241 

245  Anatomy  of  the  8nail 242 

246  Heart  and  Lungs 244 

247  Bronchi  and  Vessels  in  Situ...  245 

248  Thoracic  Viscera  in  Situ 246 

249  Lung  LET 247 

250  Diagramatic  Section  of  Thora- 

cic Viscera 249 

251  Capillaries  of  Human  Lung...  250 

252  Magnified  Section  of  Lung 250 

253  Termination  of  Bronchus 251 

254  Bronchial  Tube  laid  open 251 

255  Lateral  View  of  Larynx 259 

256  Thyroid  Cartilage 260 

257  Arytenoid  “ 260 

258  Cricoid  “ 261 

259  Epiglottis 261 

260  Larynx 261 

261  “ 262 

262  “ 262 

263  Larynx  and  Epiglottis 263 

264  Lungs  of  a Bird 271 

265  Lungs,  etc.,  of  a Pigeon 271 

266  Lunglet  of  a Fowl 272 

267  Lungs  of  a Frog 272 

268  “ “ Serpents 273 

269  Dissected  Lung  of  Turtle 274 

270  Gills  of  Eel 274 

271  Air  Bladder  of  Fish 275 

272  Trachea  of  Water  Scorpion...  276 

273  Spiracle  of  Fly 277 

274  Lymphatics 282 

275  Lymphatic  System 283 

276  Lymphatics  of  Axilla 284 

277  Thoracic  and  Lymphatic  Ducts  285 

278  Lymphatics  of  Abdomen 286 

279  “ “ Thigh 287 

280  Diagram  of  a Gland 290 

281  Chyliferous  Vessels 290 

282  The  Spleen .<!... 293 

283  Intimate  Structure  of  Spleen.  293 

284  “ “ “ « 293 

285  “ “ “ “ 294 

286  Papillae  of  Hand 295 

287  Epidermis  of  Negro 296 

288  Pigment  Cells 296 

289  Section  of  Thumb 297 

290  Cerumen  Gland 299 

291  Parasites  of  the  Fat  Glands..  300 

292  Skin  of  Palm  of  Hand 801 

293  Perspiratory  Gland 301 


448 


INDEX  O 


FIG.  PAGE 

294  Sections  op  Human  Hair 302 

295  Skin  of  Scalp 303 

296  Boot  of  Hair 304 

297  Hair  OF  Human  Beard 305 

298  “ “ Sable 311 

299  “ “ Musk  Deer 311 

300  “ “ Squirrel 312 

301  “ “ Pecari 312 

302  Tubular  Nerve  Cells. 317 

303  Vesicular  “ “ 318 

304  Section  op  Brain,  etc 319 

805  “ “ “ 320 

306  Cerebellum 320 

307  Base  of  Brain 321 

308  Cerebro-Spinal  Axis 322 

309  Sinuses  OF  Brain 323 

310  Olfactory  Nerves 325 

811  Optic  Nerves 326 

312  Third,  Fourth,  and  Sixth  Cra- 

nial Nerves 827 

313  Trifacial  Nerve 327 

314  “ “ 328 

315  Auditory  “ 328 

816  Tenth  Pair  op  Nerves 329 

317  Nerves  of  Tongue,  etc 830 

318  Portion  op  Spinal  Cord 331 

319  Diagram  showing  Decussation  332 

320  Nervous  System 333 

821  Brachial  Plexus 334 

322  Nerves  of  Fore- Arm 334 

323  IscHiATio  Plexus 335 

324  Crural  Nerve,  etc 335 

325  Nerves  op  the  Foot 336 

326  Pacinian  Corpuscles 336 

327  Sympathetic  Nerve 338 

328  Union  of  Spinal  and  Sympa- 

thetic Nerve 339 

329  Brain  of  Squirrel 357 

330  “ “ Babbit 35T 

331  “ “ Buzzard 359 

832  “ « Turtle 360 

333  « “ Fishes 361 


834  Electrical  Appar.  of  Torpedo.  862 


CUTS. 

PAGE 


Nervous  System  op  Articulates  362 

“ •*  “ Beetle 363 

“ “ “ Argonauta  364 

Nervous  System  op  Star  Fish.  . 365 

Globe  OP  the  Eye 370 

Plan  op  the  Structure  of  the 

Eye 371 

Choroid  Coat 371 

The  Iris 372 

The  Eye  Dissected 372 

Microscopic  Section  op  the  Re- 
tina  873 

Crystalline  Lens,  Front  View  874 
“ “ Side  View..  374 

Lens  at  Different  Ages 374 

Eyelids  & Lachrymal  Glands..  375 

Lachrymal  Canals 376 

View  op  Eye  and  Append- 
ages  376 

Meibomian  Glands 377 

A Single  Meibomian  Gland....  377 

Muscles  of  the  Eye 377 

Head  and  Eye  op  the  Bee 886 

Section  op  one  Facet 386 

Eye  of  Trilobite 387 

The  Left  Ear 389 

External  and  Internal  Ear  . . 389 

Cavity  of  the  Tympanum 390 

Membrana  Tympani 391 

OssicuLA  Audit  us 391 

Labyrinth  AND  Tympanum  ....  392 
Cochlea  without  the  Nerve...  392 
Nerve  without  the  Cochlea...  393 
Nerves  of  Extremity  of  Thumb  400 

Papillae  op  the  Palm 400 

Foot  of  a Fly 405 

Human  Tongue 406 

Papilla  op  Tongue 407 

Head  op  Woodpecker 410 

Tongue  of  Fly 411 

Cartilages  op  Nose 412 

Section  of  Nostrils 413 


F 

pig. 

835 

336 

337 

338 

339 

340 

341 

342 

343 

844 

345 

346 

347  : 

348 

349 

350 

351  : 

352 

353  : 

354 

355  I 

356  : 

357  ' 

358  : 

359 

360  : 

361 

362  ; 

363 

364 

365 

366 

367 

368 

369 

370 

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372 

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